BACKGROUND OF THE INVENTION
[0001] The present invention relates to novel substituted indole compounds having nitric
oxide synthase (NOS) inhibitory activity, to pharmaceutical and diagnostic compositions
containing them, and to their medical use, particularly as compounds for the treatment
of stroke, reperfusion injury, neurodegenerative disorders, head trauma, coronary
artery bypass graft (CABG) associated neurological damage, migraine with and without
aura, migraine with allodynia, chronic tension type headache (CTTH), neuropathic pain,
post-stroke pain, and chronic pain.
[0002] Nitric oxide (NO) has diverse roles both in normal and pathological processes, including
the regulation of blood pressure, in neurotransmission, and in the macrophage defense
systems (
Snyder et al., Scientific American, May 1992:68). NO is synthesized by three isoforms of nitric oxide synthase, a constitutive form
in endothelial cells (eNOS), a constitutive form in neuronal cells (nNOS), and an
inducible form found in macrophage cells (iNOS). These enzymes are homodimeric proteins
that catalyze a five-electron oxidation of L-arginine, yielding NO and citrulline.
The role of NO produced by each of the NOS isoforms is quite unique. Overstimulation
or overproduction of individual NOS isoforms, especially nNOS and iNOS, plays a role
in several disorders, including septic shock, arthritis, diabetes, ischemia-reperfusion
injury, pain, and various neurodegenerative diseases (
Kerwin, et al., J. Med. Chem. 38:4343, 1995), while m inhibition of eNOS function leads to unwanted effects such as enhanced
white cell and platelet activation, hypertension and increased atherogenesis (
Valance and Leiper, Nature Rev. Drug Disc.2002, 1, 939).
[0003] NOS inhibitors have the potential to be used as therapeutice agents in many disorders.
However, the preservation of physiologically important nitric oxide synthase function
suggests the desirability of the development of isoform-selective inhibitors that
preferentially inhibit nNOS over eNOS.
SUMMARY OF THE INVENTION
[0004] It has been found that certain 5- and 6-amidine substituted indole compounds are
nitric oxide synthase (NOS) inhibitors, and are particularly inhibitory for the nNOS
isoform.
[0005] The invention features a compound having the formula:
or a pharmaceutically acceptable salt or prodrug thereof, wherein, R
1 is H, optionally substituted C
1-6 alkyl, optionally substituted C
1-4 alkaryl, or optionally substituted C
1-4 alkheterocyclyl; each of R
2 and R
3 is, independently, H, Hal, optionally substituted C
1-6 alkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 bridged heterocyclyl, optionally substituted C
1-4 bridged alkheterocyclyl, optionally substituted C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl; and wherein said prodrug of the compound of formula (1) is a phenyl
ester, aliphatic (C
8-24) ester, acyloxymethyl ester, carbamate, or an amino acid ester; each of R
4 and R
7 is, independently, H, F, C
1-6 alkyl, or C
1-6 alkoxy; R
5 is H, R
5AC(NH)NH(CH
2)
r5 or R
5BNHC(S)NH(CH
2)
r5, wherein r5 is an integer from 0 to 2, R
5A is optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, optionally substituted C
1-4 alkheterocyclyl, optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkaryl, optionally substituted aryloyl or optionally substituted C
1-4 thioalkheterocyclyl; R
5B is optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkaryl, or optionally substituted C
1-4 thioalkheterocyclyl, wherein thioalkoxy represents an alkyl group attached to the
parent molecular group through a sulfur bond, wherein thioalkhetero-cyclyl represents
a thioalkoxy group substituted with a hetero-cyclyl group; and R
6 is H or R
6AC(NA)NH(CH
2)
r6 or R
6BNHC(S)NH(CH
2)
r6, wherein r6 is an integer from 0 to 2, R
6A is optionally substituted C
1-6 alkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, optionally substituted C
1-4 alkheterocyclyl, optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkaryl, optionally substituted aryloyl, or optionally substituted C
1-4 thioalkheterocyclyl; R
6B is optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, optionally substituted C
1-4 alkheterocyclyl, optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkoxy, optionally substituted aryloyl, or optionally substituted C
1-4 thioalkheterocyclyl, wherein one, but not both, of R
5 and R
6 is H.
[0006] In certain embodiments, R
1 is H, optionally substituted C
1-6 alkyl, optionally substituted C
1-4 alkaryl, or optionally substituted C
1-4, alkheterocyclyl; each of R
2 and R
3 is, independently, H, Hal, optionally substituted C
1-6 alkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl; each of R
4 and R
7 is, independently, H, F, C
1-6 alkyl, or C
1-6 alkoxy; R
5 is H or R
5AC(NH)NH(CH
2)
r5, wherein r5 is an integer from 0 to 2, R
5A is optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, optionally substituted C
1-4 alkheterocyclyl, optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkaryl, or optionally substituted C
1-4 thioalkheterocyclyl; and R
6 is H or R
6AC(NH)NH(CH
2)
r6, wherein r6 is an integer from 0 to 2, R
6A is optionally substituted C
1-6 alkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, optionally substituted C
2-9 heterocyclyl, optionally substituted C
1-4 alkheterocyclyl, optionally substituted C
1-6 thioalkoxy, optionally substituted C
1-4 thioalkaryl, or optionally substituted C
1-4 thioalkheterocyclyl.
[0007] In one embodiment, R
5A is thiomethoxy, thioethoxy, thio-n-propyloxy, thio-i-propyloxy, thio-n-butyloxy,
thio-i-butyloxy, thio-t-butyloxy, phenyl, benzyl, 2-thienyl, 3-thienyl, 2-furanyl,
3-furanyl, 2-oxazole, 4-oxazole, 5-oxazole, 2-thiazole, 4-thiazole, 5-thiazole, 2-isoxazole,
3-isoxazole, 4-isoxazole, 2-isothiazole, 3-isothiazole, and 4-isothiazole.
[0008] In one embodiment R
6A is methyl, fluoromethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, thiomethoxy,
thioethoxy, thio-n-propyloxy, thio-i-propyloxy, thio-n-butyloxy, thio-i-butyloxy,
thio-t-butyloxy, phenyl, benzyl, 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-oxazole,
4-oxazole, 5-oxazole, 2-thiazole, 4-thiazole, 5-thiazole, 2-isoxazole, 3-isoxazole,
4-isoxazole, 2-isothiazole, 3-isothiazole, and 4-isothiazole.
[0009] In certain embodiments, one or more of R
1, R
2, and R
3 is not H. In one embodiment R
1 is (CH
2)
mlX
1, wherein X
1 is selected from the group consisting of:
wherein
each of R
1A and R
1B is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl; each of R
1C and R
1D is, independently, H, OH, CO
2R
1E, or NR
1FR
1G, wherein each of R
1E, R
1F, and R
1G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
1C and R
1D together with the carbon they are bonded to are C=O; Z
1 is NR
1H, NC(O)R
1H, NC(O)OR
1H, NC(O)NHR
1H, NC(S)R
1H, NC(S)NHR
1H, NS(O)
2R
1H, O, S, S(O), or S(O)
2, wherein R
1H is H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl; m1 is an integer of 2 to 6; n1 is an integer of 1 to 4; p1 is an
integer of 0 to 2; and q1 is an integer of 0 to 5.
[0010] In a further embodiment R
2 is (CH
2)
m2X
2, wherein X
2 is selected from the group consisting of:
wherein
each of R
2A and R
2B is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
each of R
2C and R
2D is, independently, H, OH, CO
2R
2E, or NR
2FR
2G, wherein each of R
2E, R
2F, and R
2G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
2C and R
2D together with the carbon they are bonded to are C=O;
Z
2 is NR
2H, NC(O)R
2H, NC(O)OR
2H, NC(O)NHR
2H, NC(S)R
2H, NC(S)NHR
2H, NS(O)
2R
2H, O, S, S(O), or S(O)
2, wherein R
2H is H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
m2 is an integer of 0 to 6;
n2 is an integer of 1 to 4;
p2 is an integer of 0 to 2; and
q2 is an integer of 0 to 5.
[0011] In another embodiment R
3 is (CH
2)
m3X
3, wherein X
3 is selected from the group consisting of:
wherein
each of R
3A and R
3B is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
each of R
3C and R
3D is, independently, H, OH, CO
2R
3E, or NR
3FR
3G, wherein each of
R3E, R
3F, and R
3G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
3C and R
3D together with the carbon they are bonded to are C=O;
Z
3 is NR
3H, NC(O)R
3H, NC(O)OR
3H, NC(O)NHR
3H, NC(S)R
3H, NC(S)NHR
3H, NS(O)
2R
3H, O, S, S(O), or S(O)
2, wherein R
3H is H, optionally substituted C
1-6alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
m3 is an integer of 0 to 6;
n3 is an integer of 1 to 4;
p3 is an integer of 0 to 2; and
q3 is an integer of 0 to 5.
[0012] In another embodiment, R
1 is (CH
2)
m3X
1 wherein X
1 is selected from the group consisting of:
wherein
each of R
3C and R
3D is, independently, H, OH, CO
2R
3E, or NR
3FR
3G, wherein each of R
3E, R
3F, and R
3G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
3C and R
3D together with the carbon they are bonded to are C=O; Z
3 is NC(NH)R
3H, wherein R
3H is H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl; m3 is an integer of 0 to 6; n3 is an integer of 1 to 4; p3 is an
integer of 0 to 2; and q3 is an integer of 0 to 5.
[0013] In a further embodiment R
2 is (CH
2)
m3X
2, wherein X
2 is selected from the group consisting of:
wherein
each of R
3C and R
3D is, independently, H, OH, CO
2R
3E, or NR
3FR
3G, wherein each of R
3E, R
3F, and R
3G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
3C and R
3D together with the carbon they are bonded to are C=O;
Z
3 is NC(NH)R
3H, wherein R
3H is H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
m3 is an integer of 0 to 6;
n3 is an integer of 1 to 4;
p3 is an integer of 0 to 2; and
q3 is an integer of 0 to 5.
[0014] In another embodiment R
3 is (CH
2)
m3X
3, wherein X
3 is selected from the group consisting of:
wherein
each of R
3C and R
3D is, independently, H, OH, CO
2R
3E, or NR
3FR
3G, wherein each of R
3E, R
3F, and R
3G is, independently, H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl, or R
3C and R
3D together with the carbon they are bonded to are C=O;
Z
3 is NC(NH)R
3H, wherein R
3H is H, optionally substituted C
1-6 alkyl, optionally substituted C
3-8 cycloalkyl, optionally substituted C
6-10 aryl, optionally substituted C
1-4 alkaryl, C
2-9 heterocyclyl, or optionally substituted C
1-4 alkheterocyclyl;
m3 is an integer of 0 to 6;
n3 is an integer of 1 to 4;
p3 is an integer of 0 to 2; and
q3 is an integer of 0 to 5.
[0015] In one embodiment R
2 is
wherein each of R
2J2, R
2J3, R
2J4, R
2J5, and R
2J6 is, independently, C
1-6 alkyl; OH; C
1-6 alkoxy; SH; C
1-6 thioalkoxy; Halo; NO
2; CN; CF
3; OCF
3; NR
2JaR
2Jb, where each of R
2Ja and R
2Jb is, independently, H or C
1-6 alkyl; C(O)R
2Jc, where R
2Jc is H or C
1-6 alkyl; CO
2R
2Jd, where R
2Jd is H or C
1-6 alkyl; tetrazolyl; C(O)NR
2JeR
2Jf, where each of R
2Je and R
2Jf is, independently, H or C
1-6 alkyl; OC(O)R
2Jg, where R
2Jg is C
1-6 alkyl; NHC(O)R
2Jh, where R
2Jh is H or C
1-6 alkyl; SO
3H; S(O)
2NR
2JiR
2Jj, where each of R
2Ji and R
2Jj is, independently, H or C
1-6 alkyl; S(O)R
2Jk, where R
2Jk is C
1-6 alkyl; and S(O)
2R
2Jl, where R
2Jl is C
1-6 alkyl.
[0016] In one embodiment R
3 is
wherein each of R
3J2, R
3J3, R
3J4, R
3J5, and R
3J6 is, independently, C
1-6 alkyl; OH; C
1-6alkoxy; SH; C
1-6thioalkoxy; Halo; NO
2; CN; CF
3; OCF
3; NR
3JaR
3Jb, where each of R
3Ja and R
3Jb is, independently, H or C
1-6 alkyl; C(O)R
3Jc, where R
3Jc is H or C
1-6 alkyl; CO
2R
3Jd, where R
3Jd is H or C
1-6 alkyl; tetrazolyl; C(O)NR
3JcR
3Jf, where each of R
3Je and R
3Jf is, independently, H or C
1-6 alkyl; OC(O)R
3Jg, where R
3Jg is C
1-6 alkyl; NHC(O)R
3Jh, where R
3Jh is H or C
1-6 alkyl; SO
3H; S(O)
2NR
3JiR
3Jj, where each of R
3Ji and R
3Jj is, independently, H or C
1-6 alkyl; S(O)R
3Jk, where R
3Jk is C
1-6 alkyl;and S(O)
2R
3Jl, where R
3Jl is C
1-6alkyl.
[0017] In a further embodiment of the present invention said compound is selected from the
group consisting of: N-(1H-indol-5-yl)-thiophene-2-carboxamidine; N-[1-(2-dimethylamino-ethyl)-1H-indol-6-yl]-thiophene-2-carboxamidine;
N-{1-[2-(1-methylpyrrolidin-2-yl)-ethyl]-1H-indol-6-yl}-thiophene-2-carboxamidine;
N-[1-(2-pyrrolidin-1-yl-ethyl)-1H-indol-6-yl]-thiophene-2-carboxamidine; N-(1-phenethyl-1H-indol-6-yl)-thiophene-2-carboxamidine;
N-[3-(2-dimethylamino-ethyl)-1H-indol-5-yl]-thiophene-2-carboxamidine; N-(1-{2-[2-(4-bromo-phenyl)-ethylamino]-ethyl}-1H-indol-6-yl)-thiophene-2-carboxamidine;
(+)-N-{1-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-1H-indol-6-yl}-thiophene-2-carboxamidine;
(-)-N-{1-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-1H-indol-6-yl}-thiophene-2-carboxamidine;
N-[1-(1-methyl-azepan-4-yl)-1H-indol-6-yl]-thiophene-2-carboxamidine; and N-[1-(2-piperidin-l-yl-ethyl)-1H-indol-6-yl]-thiophene-2-carboxamidine.
[0018] In one embodiment R
1 or R
3 is
wherein Z is NR
x, R
x is methyl, o is an integer from 0-3, p is an integer from 1 to 2, q is an integer
from 0 to 2, r is an integer from 0 to 1, s is an integer from 1 to 3 , u is an integer
from 0 to 1, and t is an integer from 5 to 7, and wherein said R
1 or R
3 substituent includes 0 to 6 carbon-carbon double bonds or 0 or 1 carbon-nitrogen
double bonds.
[0019] In one embodiment, a compound of the invention selectively inhibits neuronal nitric
oxide synthase (nNOS) over endothelial nitric oxide synthase (eNOS) or inducible nitric
oxide synthase (iNOS). In one embodiment the compound of the invention selectively
inhibits nNOS over both eNOS and iNOS. Preferably, the IC
50 or K
i value observed for the compound when tested is at least 2 times lower in the nNOS
assay than in the eNOS and/or iNOS assays. More preferably, the IC
50 or K
i value is at least 5 times lower. Most preferably, the IC
50 or K
i value is 20, or even 50 times lower. In one embodiment, the IC
50 or K
i value is between 2 times and 50 times lower.
[0020] In one embodiment the compounds of the invention have the formula:
wherein X is O or S.
[0021] In another embodiment the compounds of the invention have the formula:
wherein X is O or S.
[0022] In another example of the invention, compounds of formula I wherein R
5 is R
5AC(NH)NH(CH
2)
r5 or R
5ANHC(S)NH(CH
2)
r5, R
6, R
2, and R
1 are H, and R
3 is (CH
2)
m3X
1 also bind to the serotonin 5HT1D/1B receptors. Preferably the IC
50 or K
i value is between 10 and 0.001 micromolar. More preferably, the IC
50 or K
i is less than 1 micromolar. Most preferably, the IC
50 or K
i is less than 0.1.
[0023] Specific exemplary compounds are described herein.
[0025] In another embodiment the compound of the invention is selected from the group consisting
of:
[0026] The invention further features pharmaceutical compositions including a compound of
the invention and a pharmaceutically acceptable excipient
[0027] In another aspect, the invention features a medicament containing an effective amount
of the compound of the invention for treating a condition in a mammal, in particular
a human, caused by the action of nitric oxide synthase (NOS). Examples of conditions
that can be prevented or treated include migraine headache (with or without aura),
chronic tension type headache (CTTH), migraine with allodynia, neuropathic pain, post-stroke
pain, chronic headache, chronic pain, acute spinal cord injury, diabetic neuropathy,
trigeminal neuralgia, diabetic nephropathy, an inflammatory disease, stroke, reperfusion
injury, head trauma, cardiogenic shock, CABG associated neurological damage, HCA,
AIDS associated dementia, neurotoxicity, Parkinson's disease, Alzheimer's disease,
ALS, Huntington's disease, multiple sclerosis, metamphetamine-induced neurotoxicity,
drug addiction, morphine/opioid induced tolerance, dependence, hyperalgesia, or withdrawal,
ethanol tolerance, dependence, or withdrawal, epilepsy, anxiety, depression, attention
deficit hyperactivity disorder, and psychosis. Compounds of the invention are particularly
useful for treating stroke, reperfusion injury, neurodegeneration, head trauma, CABG
associated neurological damage, migraine headache (with or without aura), migraine
with allodynia, chronic tension type headache, neuropathic pain, post-stroke pain,
opioid induced hyperalgesia, or chronic pain. In particular, 3,5-substituted indole
compounds are useful for treating migraine, with or without aura, and CTTH.
[0028] A compound of the invention can also be used in combination with one or more other
therapeutic agents for the prevention or treatment of one of the aforementioned conditions.
Examples of classes of therapeutic agents and some specific examples that are useful
in combination with a compound of the invention are listed in Table 1.
[0029] In one embodiment the medicament further comprises an opioid, in particular wherein
said opioid is alfentanil, butorphanol, buprenorphine, dextromoramide, dezocine, dextropropoxyphene,
codeine, dihydrocodeine, diphenoxylate, etorphine, fentanyl, hydrocodone, hydromorphone,
ketobemidone, loperamide, levorphanol, levomethadone, meperidine, meptazinol, methadone,
morphine, morphine-6-glucuronide, nalbuphine, naloxone, oxycodone, oxymorphone, pentazocine,
pethidine, piritramide, propoxylphene, remifentanil, sulfentanyl, tilidine, or tramadol.
[0030] In another embodiment the medicament further comprises an antidepressant.
[0031] In particular, the antidepressant is (a) a selective serotonin re-uptake inhibitor,
in particular wherein said selective serotonin re-uptake inhibitor is citalopram,
escitalopram, fluoxetine, fluvoxamine, paroxetine or sertraline; (b) a norepinephrine-reuptake
inhibitor, in particular wherein said norepinephrine-reuptake inhibitor is amitriptyline,
desmethylamitriptyline, clomipramine, doxepin, imipramine, imipramine oxide, trimipramine;
adinazolam, amiltriptylinoxide, amoxapine, desipramine, maprotiline, nortriptyline,
protriptyline, amineptine, butriptyline, demexiptiline, dibenzepin, dimetacrine, dothiepin,
fluacizine, iprindole, lofepramine, melitracen, metapramine, norclolipramine, noxiptilin,
opipramol, perlapine, pizotyline, propizepine, quinupramine, reboxetine, or tianeptine;
(c) a selective noradrenaline/norepinephrine reuptake inhibitor, in particular wherein
said selective noradrenaline/norepinephrine reuptake inhibitor is atomoxetine, bupropion,
reboxetine, or tomoxetine; (d) a dual serotonin/norepinephrine reuptake inhibitor,
in particular wherein said dual serotonin/norepinephrine reuptake inhibitor is duloxetine,
milnacipran, mirtazapine, nefazodone, or venlafaxine; (e) a monoamine oxidase inhibitor,
in particular wherein said monoamine oxidase inhibitor is amiflamine, iproniazid,
isocarboxazid, M-3-PPC (Draxis), moclobemide, pargyline, phenelzine, tranylcypromine,
or vanoxerine; (f) a reversible monoamine oxidase type A inhibitor, in particular
wherein said reversible monoamine oxidase type A inhibitor is bazinaprine, befloxatone,
brofaromine, cimoxatone, or clorgyline; (g) a tricyclic, in particular wherein said
tricyclic is amitriptyline, clomipramine, desipramine, doxepin, imipramine, maprotiline,
nortryptyline, protriptyline, or trimipramine; (h) adinazolam, alaproclate, amineptine,
amitriptyline/chlordiazepoxi- de combination, atipamezole, azamianserin, bazinaprine,
befuraline, bifemelane, binodaline, bipenamol, brofaromine, caroxazone, cericlamine,
cianopramine, cimoxatone, citalopram, clemeprol, clovoxamine, dazepinil, deanol, demexiptiline,
dibenzepin, dothiepin, droxidopa, enefexine, estazolam, etoperidone, femoxetine, fengabine,
fezolamine, fluotracen, idazoxan, indalpine, indeloxazine, iprindole, levoprotiline,
lithium, litoxetine; lofepramine, medifoxamine, metapramine, metralindole, mianserin,
milnacipran, minaprine, mirtazapine, montirelin, nebracetam, nefopam, nialamide, nomifensine,
norfluoxetine, orotirelin, oxaflozane, pinazepam, pirlindone, pizotyline, ritanserin,
rolipram, sercloremine, setiptiline, sibutramine, sulbutiamine, sulpiride, teniloxazine,
thozalinone, thymoliberin, tianeptine, tiflucarbine, trazodone, tofenacin, tofisopam,
toloxatone, tomoxetine, veralipride, viloxazine, viqualine, zimelidine, or orzometrapine.
[0032] In another embodiment the medicament further comprises an antiepileptic, in particular
wherein said antiepileptic is carbamazepine, flupirtine, gabapentin, lamotrigine,
oxcarbazepine, phenyloin, retigabine, topiramate, or valproate.
[0033] In a further embodiment medicament further comprises a non-steroidal anti-inflammatory
drug (NSAID), in particular wherein said NSAID is acemetacin, aspirin, celecoxib,
deracoxib, diclofenac, diflunisal, ethenzamide, etofenamate, etoricoxib, fenoprofen,
flufenamic acid, flurbiprofen, lonazolac, lornoxicam, ibuprofen, indomethacin, isoxicam,
kebuzone, ketoprofen, ketorolac, naproxen, nabumetone, niflumic acid, sulindac, tolmetin,
piroxicam, meclofenamic acid, mefenamic acid, meloxicam, metamizol, mofebutazone,
oxyphenbutazone, parecoxib, phenidine, phenylbutazone, piroxicam, propacetamol, propyphenazone,
rofecoxib, salicylamide, suprofen, tiaprofenic acid, tenoxicam, valdecoxib, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluoro-benzenesulfonamide,
N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide, 2-(3,4-difluorophenyl)-4-(3-hydroxy-3-methylbutoxy)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone,
or 2-(3,5-difluorophenyl)-3-[4-(methylsulfonyl)phenyl]-2-cyclopenten-1-one).
[0034] Other agents useful in combination with a compound of the invention, include antiarrhythmics;
DHP-sensitive L-type calcium channel antagonists; omega-conotoxin (Ziconotide)-sensitive
N-type calcium channel antagonists; P/Q-type calcium channel antagonists; adenosine
kinase antagonists; adenosine receptor A
1 agonists; adenosine receptor A
2a antagonists; adenosine receptor A
3 agonists; adenosine deaminase inhibitors; adenosine nucleoside transport inhibitors;
vanilloid VR1 receptor agonists; Substance P/NK
1 antagonists; cannabinoid CB1/CB2 agonists; GABA-B antagonists; AMPA and kainate antagonists,
metabotropic glutamate receptor antagonists; alpha-2-adrenergic receptor agonists;
nicotinic acetylcholine receptor agonists (nAChRs); cholecystokinin B antagonists;
sodium channel blockers; a K
ATP potassium channel, K
v1.4 potassium channel, Ca
2+-activated potassium channel, SK potassium channel, BK potassium channel, IK potassium
channel, or KCNQ2/3 potassium channel opening agent (eg. retigabine); 5HT
1A agonists; muscarinic M3 antagonists, M1 agonists, M2/M3 partial agonist/antagonists;
and antioxidants.
[0035] Accordingly, in one embodiment the medicament further comprises an antiarrhythmic,
a GABA-B antagonist, or an alpha-2-adrenergic receptor agonist.
[0036] In one embodiment the medicament further comprises a serotonin 5HT
1B/1D agonist, in particular wherein said serotonin 5HT
1B/1D agonist is eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan, or zolmitriptan.
[0037] In another embodiment the medicament further comprises an N-methyl-D-aspartate antagonist,
in particular wherein said N-methyl-D-aspartate antagonist is amantadine; aptiganel;
besonprodil; budipine; conantokin G; delucemine; dexanabinol; dextromethorphan; dextropropoxyphen;
felbamate; fluorofelbamate; gacyclidine; glycine; ipenoxazone; kaitocephalin; ketamine;
ketobemidone; lanicemine; licostinel; midafotel; memantine; D-methadone; D-morphine;
milnacipran; neramexane; orphenadrine; remacemide; sulfazocine; FPL-12,495 (racemide
metabolite); topiramate; (αR)-α-amino-5-chloro-1-(phosphonomethyl)-1H-benzimidazole-2-propanoic
acid; 1-aminocyclopentane-carboxylic acid; [5-(aminomethyl)-2-[[[(5
S)-9-chloro-2,3,6,7-tetrahydro-2,3-dioxo-1H-,5H-pyrido[1,2,3-de]quinoxalin-5-yl]acetyl]amino]phenoxy]-acetic
acid; α-amino-2-(2-phosphonoethyl)-cyclohexanepropanoic acid; α-amino-4-(phosphonomethyl)-benzeneacetic
acid; (3E)-2-amino-4-(phosphonomethyl)-3-heptenoic acid; 3-[(1E)-2-carboxy-2-phenylethenyl]-4,6-dichloro-1H-indole-2-carboxylic
acid; 8-chloro-2,3-dihydropyridazino[4,5-b]quinoline-1,4-dione 5-oxide salt with 2-hydroxy-N,N,N-trimethyl-ethanaminium;
N'-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-(methylthio)phenyl]-guanidine; N'-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-[(R)-methylsulfinyl]phenyl]-guanidine;
6-chloro-2,3,4,9-tetrahydro-9-methyl-2,3-dioxo-1H-indeno[1,2-b]pyrazine-9-acetic acid;
7-chlorothiokynurenic acid; (3
S,4a
R,6
S,8a
R)-decahydro-6-(phosphonomethyl)-3-isoquinolinecarboxylic acid; (-)-6,7-dichloro-1,4-dihydro-5-[3-(methoxymethyl)-5-(3-pyridinyl)-4-H-1,2,4-triazol-4-yl]-2,3-quinoxalinedione;
4,6-dichloro-3-[(E)-(2-oxo-1-phenyl-3-pyrrolidinylidene)-methyl]-1H-indole-2-carboxylic
acid; (2
R,4
S)-rel-5,7-dichloro-1,2,3,4-tetrahydro-4-[[(phenylamino)carbonyl]amino]-2-quinolinecarboxylic
acid; (3
R,4
S)-rel-3,4-dihydro-3-[4-hydroxy-4-(phenylmethyl)-1-piperidinyl]-2H-1-benzopyran-4,7-diol;
2-[(2,3-dihydro-1H-inden-2-yl)amino]-acetamide; 1,4-dihydro-6-methyl-5-[(methylamino)-methyl]-7-nitro-2,3-quinoxalinedione;
[2-(8,9-dioxo-2,6-diazabicyclo-[5.2.0]non-1(7)-en-2-yl)ethyl]-phosphonic acid; (2
R,6
S)-1,2,3,4,5,6-hexahydro-3-[(2S)-2-methoxypropyl]-6,11,11-trimethyl-2,6-methano-3-benzazocin-9-ol;
2-hydroxy-5-[[(pentafluorophenyl)methyl]amino]-benzoic acid; 1-[2-(4-hydroxy-phenoxy)ethyl]-4-[(4-methylphenyl)methyl]-4-piperidinol;
1-[4-(1H-imidazol-4-yl)-3-butynyl]-4-(phenylmethyl)-piperidine; 2-methyl-6-(phenylethynyl)-pyridine;
3-(phosphonomethyl)-L-phenylalanine; or 3,6,7-tetrahydro-2,3-dioxo-N-phenyl-1H,5H-pyrido[1,2,3-de]quinoxaline-5-acetamide.
[0038] In one embodiment the medicament further comprises a cholecystokinin B antagonist,
or a substance P antagonist.
[0039] In a further embodiment the medicament further comprises an anti-inflammatory compound,
in particular wherein said anti-inflammatory compound is aspirin, celecoxib, cortisone,
deracoxib, diflunisal, etoricoxib, fenoprofen, ibuprofen, ketoprofen, naproxen, prednisolone,
sulindac, tolmetin, piroxicam, mefenamic acid, meloxicam, phenylbutazone, rofecoxib,
suprofen, valdecoxib, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide,
N-[2-(cyclohexyloxy)-4-nitro-phenyl]methanesulfonamide, 2-(3,4-difluorophenyl)-4-(3-hydroxy-3-methylbutoxy)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone,
or 2-(3,5-difluorophenyl)-3-[4-(methylsulfonyl)phenyl]-2-cyclopenten-1-one.
[0040] In another embodiment the medicament further comprises a DHP-sensitive L-type calcium
channel antagonist, an omega-conotoxin-sensitive N-type calcium channel antagonist,
a P/Q-type calcium channel antagonist, an adenosine kinase antagonist, an adenosine
receptor A
1 agonist, an adenosine receptor A
2a antagonist, an adenosine receptor A
3 agonist, an adenosine deaminase inhibitor, an adenosine nucleoside transport inhibitor,
a vanilloid VR1 receptor agonist, a cannabinoid CB1/CB2 agonist, an AMPA receptor
antagonist, a kainate receptor antagonist, a sodium channel blocker, a nicotinic acetylcholine
receptor agonist, a K
ATP potassium channel opening agent, a K
v1.4 potassium channel opening agent, a Ca
2+-activated potassium channel opening agent, a SK potassium channel opening agent,
a BK potassium channel opening agent, an IK potassium channel opening agent, a KCNQ2/3
potassium channel opening agent, a muscarinic M3 antagonist, a muscarinic M1 agonist,
a muscarinic M2/M3 partial agonist/antagonist, or an antioxidant.
Table 1. Therapeutic agents useful in combination with compounds of the invention
Class |
Examples |
Opioid |
alfentanil, butorphanol, buprenorphine, codeine, dextromoramide, dextropropoxyphene,
dezocine, dihydrocodeine, diphenoxylate, etorphine, fentanyl, hydrocodone, hydromorphone,
ketobemidone, levorphanol, levomethadone, methadone, meptazinol, morphine, morphine-6-glucuronide,
nalbuphine, naloxone, oxycodone, oxymorphone, pentazocine, pethidine, piritramide,
remifentanil, sulfentanyl, tilidine, or tramadol |
Antidepressant (selective serotonin reuptake inhibitor) |
citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, or sertraline |
Antidepressant (norepinephrine-reuptake inhibitor) |
amitriptyline, desmethylamitriptyline, clomipramine, doxepin, imipramine, imipramine
oxide, trimipramine; adinazolam, amiltriptylinoxide, amoxapine, desipramine, maprotiline,
nortriptyline, protriptyline, amineptine, butriptyline, demexiptiline, dibenzepin,
dimetacrine, dothiepin, fluacizine, iprindole, lofepramine, melitracen, metapramine,
norclolipramine, noxiptilin, opipramol, perlapine, pizotyline, propizepine, quinupramine,
reboxetine, or tianeptine |
Antidepressant (noradrenaline/ norepinephrine reuptake inhibitor) |
atomoxetine, bupropion, reboxetine, or tomoxetine |
Antidepressant (dual serotonin/ norepinephrine reuptake inhibitor) |
duloxetine, milnacipran, mirtazapine, nefazodone, or venlafaxine |
Antidepressant (monoamine oxidase inhibitor) |
amiflamine, iproniazid, isocarboxazid, M-3-PPC (Draxis), moclobemide, pargyline, phenelzine,
tranylcypromine, or vanoxerine |
Antidepressant (reversible monoamine oxidase type A inhibitor) |
bazinaprine, befloxatone, brofaromine, cimoxatone, or clorgyline |
Antidepressant (tricyclic) |
amitriptyline, clomipramine, desipramine, doxepin, imipramine, maprotiline, nortryptyline,
protriptyline, or trimipramine |
Antidepressant (other) |
adinazolam, alaproclate, amineptine, amitriptyline/chlordiazepoxide combination, atipamezole,
azamianserin, bazinaprine, befuraline, bifemelane, binodaline, bipenamol, brofaromine,
caroxazone, cericlamine, cianopramine, cimoxatone, citalopram, clemeprol, clovoxamine,
dazepinil, deanol, demexiptiline, dibenzepin, dothiepin, droxidopa, enefexine, estazolam,
etoperidone, femoxetine, fengabine, fezolamine, fluotracen, idazoxan, indalpine, indeloxazine,
iprindole, levoprotiline, lithium, litoxetine; lofepramine, medifoxamine, metapramine,
metralindole, mianserin, milnacipran, minaprine, mirtazapine, montirelin, nebracetam,
nefopam, nialamide, nomifensine, norfluoxetine, orotirelin, oxaflozane, pinazepam,
pirlindone, pizotyline, ritanserin, rolipram, sercloremine, setiptiline, sibutramine,
sulbutiamine, sulpiride, teniloxazine, thozalinone, thymoliberin, tianeptine, tiflucarbine,
trazodone, tofenacin, tofisopam, toloxatone, tomoxetine, veralipride, viloxazine,
viqualine, zimelidine, or zometapine |
Antiepileptic |
carbamazepine, flupirtine, gabapentin, lamotrigine, oxcarbazepine, phenyloin, retigabine,
topiramate, or valproate |
Non-steroidal anti-inflammatory drug (NSAID) |
acemetacin, aspirin, celecoxib, deracoxib, diclofenac, diflunisal, ethenzamide, etofenamate,
etoricoxib, fenoprofen, flufenamic acid, flurbiprofen, lonazolac, lornoxicam, ibuprofen,
indomethacin, isoxicam, kebuzone, ketoprofen, ketorolac, naproxen, nabumetone, niflumic
acid, sulindac, tolmetin, piroxicam, meclofenamic acid, mefenamic acid, meloxicam,
metamizol, mofebutazone, oxyphenbutazone, parecoxib, phenidine, phenylbutazone, piroxicam,
propacetamol, propyphenazone, rofecoxib, saticylamide, suprofen, tiaprofenic acid,
tenoxicam, valdecoxib, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide,
N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide, 2-(3,4-difluorophenyl)-4-(3-hydroxy-3-methylbutoxy)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone,
or 2-(3,5-difluorophenyl)-3-[4-(methylsulfonyl)phenyl]-2-cyclopenten-1-one). |
5HT1B/1D agonist |
eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan, or zolmitriptan |
Anti-inflammatory compounds |
aspirin, celecoxib, cortisone, deracoxib, diflunisal, etoricoxib, fenoprofen, ibuprofen,
ketoprofen, naproxen, prednisolone, sulindac, tolmetin, piroxicam, mefenamic acid,
meloxicam, phenylbutazone, rofecoxib, suprofen, valdecoxib, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide,
N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide, 2-(3,4-difluorophenyl)-4-(3-hydroxy-3-methylbutoxy)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone,
or 2-(3,5-difluoropbenyl)-3-[4-(methylsulfonyl)phenyl]-2-cyclopenten-1-one |
N-methyl-D-aspartate antagonist |
amantadine; aptiganel; besonprodil; budipine; conantokin G; delucemine; dexanabinol;
dextromethorphan; dextropropoxyphen;felbamate; fluorofelbamate; gacyclidine; glycine;
ipenoxazone; kaitocephalin; ketamine; ketobemidone; lanicemine; licostinel; midafotel;
memantine; D-methadone; D-morphine; milnacipran; neramexane; orphenadrine; remacemide;
sulfazocine; FPL-12,495 (racemide metabolite); topiramate; (αR)-α-amino-5-chloro-1-(phosphonomethyl)-1H-benzimidazole-2-propanoic
acid; 1-aminocyclopentane-carboxylic acid; [5-(aminomethyl)-2-[[[(5S)-9-chloro-2,3,6,7-tetrahydro-2,3-dioxo-1H-,5H-pyrido[1,2,3-de]quinoxalin-5-yl]acetyl]amino]phenoxy]-acetic
acid; α-amino-2-(2-phosphonoethyl)-cyclohexanepropanoic acid; α-amino-4-(phosphonomethyl)-benzeneacetic
acid; (3E)-2-amino-4-(phosphonomethyl)-3-heptenoic acid; 3-[(1E)-2-carboxy-2-phenylethenyl]-4,6-dichloro-1H-indole-2-carboxylic
acid; 8-chloro-2,3-dihydropyridazino[4,5-b]quinoline-1,4-dione 5-oxide salt with 2-hydroxy-N,N,N-trimethyl-ethanaminium;
N'-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-(methylthio)phenyl]-guanidine; N'-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-[(R)-methylsulfinyl]phenyl]-guanidine; 6-chloro-2,3,4,9-tetrahydro-9-methyl-2,3-dioxo-1H-indeno[1,2-b]pyrazine-9-acetic
acid; 7-chlorothiokynurenic acid; (3S,4aR,6S,8aR)-decahydro-6-(phosphonomethyl)-3-isoquinolinecarboxylic acid; (-)-6,7-dichloro-1,4-dihydro-5-[3-(methoxymethyl)-5-(3-pyridinyl)-4-H-1,2,4-triazol-4-yl]-2,3-quinoxalinedione;
4,6-dichloro-3-[(E)-(2-oxo-1-phenyl-3-pyrrolidinylidene)methyl]-1H-indole-2-carboxylic
acid; (2R,4S)-rel-5,7-dichloro-1,2,3,4-tetrahydro-4-[[(phenylamino)carbonyl]amino]-2-quinolinecarboxylic
acid; (3R,4S)-rel-3,4-dihydro-3-[4-hydroxy-4-(phenylmethyl)-1-piperidinyl-]-2H-1-benzopyran-4,7-diol;
2-[(2,3-dihydro-1H-inden-2-yl)amino]-acetamide; 1,4-dihydro-6-methyl-5-[(methylamino)methyl]-7-nitro-2,3-quinoxalinedione;
[2-(8,9-dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)ethyl]-phosphonic acid; (2R,6S)-1,2,3,4,5,6-hexahydro-3-[(2S)-2-methoxypropyl]-6,11,11-trimethyl-2,6-methano-3-benzazocin-9-ol;
2-hydroxy-5-[[(pentafluorophenyl)methyl]amino]-benzoic acid; 1-[2-(4-hydroxyphenoxy)ethyl]-4-[(4-methylphenyl)methyl]-4-piperidinol;
1-[4-(1H-imidazol-4-yl)-3-butynyl]-4-(phenylmethyl)-piperidine; 2-methyl-6-(phenylethynyl)-pyridine;
3-(phosphonomethyl)-L-phenylalanine; or 3,6,7-tetrahydro-2,3-dioxo-N-phenyl-1H,5H-pyrido
[1,2,3-de]quinoxaline-5-acetamide |
[0041] Asymmetric or chiral centers may exist in any of the compounds of the present invention.
The present invention contemplates the various stereoisomers and mixtures thereof.
Individual stereoisomers of compounds of the present invention are prepared synthetically
from commercially available starting materials which contain asymmetric or chiral
centers or by preparation of mixtures of enantiometic compounds followed by resolution
well-known to those of ordinary skill in the art. These methods of resolution are
exemplified by (1) attachment of a racemic mixture of enantiomers, designated (+/-),
to a chiral auxiliary, separation of the resulting diastereomers by recrystallization
or chromatography and liberation of the optically pure product from the auxiliary
or (2) direct separation of the mixture of optical enantiomers on chiral chromatographic
columns. Enantiomers are designated herein by the symbols "R," or "S," depending on
the configuration of substituents around the chiral carbon atom. Alternatively, enantiomers
are designated as (+) or (-) depending on whether a solution of the enantiomer rotates
the plane of polarized light clockwise or counterclockwise, respectively.
[0042] Geometric isomers may also exist in the compounds of the present invention. The present
invention contemplates the various geometric isomers and mixtures thereof resulting
from the arrangement of substituents around a carbon-carbon double bond and designates
such isomers as of the Z or E configuration, where the term "Z" represents substituents
on the same side of the carbon-carbon double bond and the term "E" represents substituents
on opposite sides of the carbon-carbon double bond. It is also recognized that for
structures in which tautomeric forms are possible, the description of one tautomeric
form is equivalent to the description of both, unless otherwise specified. For example,
amidine structures of the formula -C(=NR
Q)NHR
T and -C(NHR
Q)=NR
T, where R
T and R
Q are different, are equivalent tautomeric structures and the description of one inherently
includes the other.
[0043] It is understood that substituents and substitution patterns on the compounds of
the invention can be selected by one of ordinary skill in the art to provide compounds
that are chemically stable and that can be readily synthesized by techniques known
in the art, as well as those methods set forth below, from readily available starting
materials. If a substituent is itself substituted with more than one group, it is
understood that these multiple groups may be on the same carbon or on different carbons,
so long as a stable structure results.
[0044] Other features and advantages of the invention will be apparent from the following
description and the claims.
Definitions
[0045] The terms "acyl" or "alkanoyl," as used interchangeably herein, represent an alkyl
group, as defined herein, or hydrogen attached to the parent molecular group through
a carbonyl group, as defined herein, and is exemplified by formyl, acetyl, propionyl,
butanoyl and the like. Exemplary unsubstituted acyl groups include from 2 to 7 carbons.
[0046] The terms "C
x-y alkaryl" or "C
x-y alkylenearyl," as used herein, represent a chemical substituent of formula -RR',
where R is an alkylene group of x to y carbons and R' is an aryl group as defined
elsewhere herein. Similarly, by the terms "C
x-yalkheteroaryl" "C
x-yalkyleneheteroaryl," is meant a chemical substituent of formula -RR", where R is an
alkylene group of x to y carbons and R" is a heteroaryl group as defined elsewhere
herein. Other groups preceeded by the prefix "alk-" or "alkylene-" are defined in
the same manner. Exemplary unsubstituted alkaryl groups are of from 7 to 16 carbons.
[0047] The term "alkcycloalkyl" represents a cycloalkyl group attached to the parent molecular
group through an alkylene group.
[0048] The term "alkenyl," as used herein, represents monovalent straight or branched chain
groups of, unless otherwise specified, from 2 to 6 carbons containing one or more
carbon-carbon double bonds and is exemplified by ethenyl, 1-propenyl, 2-propenyl,
2-methyl- 1-propenyl, 1-butenyl, 2-butenyl, and the like.
[0049] The term "alkheterocyclyl" represents a heterocyclic group attached to the parent
molecular group through an alkylene group. Exemplary unsubstituted alkheterocyclyl
groups are of from 3 to 14 carbons.
[0050] The term "alkoxy" represents a chemical substituent of formula -OR, where R is an
alkyl group of 1 to 6 carbons, unless otherwise specified.
[0051] The term "alkoxyalkyl" represents an alkyl group which is substituted with an alkoxy
group. Exemplary unsubstituted alkoxyalkyl groups include between 2 to 12 carbons.
[0052] The terms "alkyl" and the prefix "alk-," as used herein, are inclusive of both straight
chain and branched chain saturated groups of from 1 to 6 carbons, unless otherwise
specified. Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-,
iso- and tert-butyl, neopentyl, and the like, and may be optionally substituted with
one, two, three or, in the case of alkyl groups of two carbons or more, four substituents
independently selected from the group consisting of: (1) alkoxy of one to six carbon
atoms; (2) alkylsulfinyl of one to six carbon atoms; (3) alkylsulfonyl of one to six
carbon atoms; (4) amino; (5) aryl; (6) arylalkoxy; (7) aryloyl; (8) azido; (9) carboxaldehyde;
(10) cycloalkyl of three to eight carbon atoms; (11) halo; (12) heterocyclyl; (13)
(heterocycle)oxy; (14) (heterocycle)oyl; (15) hydroxy; (16) N-protected amino; (17)
nitro; (18) oxo; (19) spiroalkyl of three to eight carbon atoms; (20) thioalkoxy of
one to six carbon atoms; (21) thiol; (22) -CO
2R
A, where R
A is selected from the group consisting of (a) alkyl, (b) aryl and (c) alkaryl, where
the alkylene group is of one to six carbon atom; (23) -C(O)NR
BR
C, where each of R
B and R
C is, independently, selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(24) -SO
2R
D, where R
D is selected from the group consisting of (a) alkyl, (b) aryl and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (25) -SO
2NR
ER
F, where each of R
E and R
F is, independently, selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
and (26) -NR
GR
H, where each of R
G and R
H is, independently, selected from the group consisting of (a) hydrogen; (b) an N-protecting
group; (c) alkyl of one to six carbon atoms; (d) alkenyl of two to six carbon atoms;
(e) alkenyl of two to six carbon atoms; (f) aryl; (g) alkaryl, where the alkylene
group is of one to six carbon atoms; (h) cycloalkyl of three to eight carbon atoms;
and (i) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms,
and the alkylene group is of one to ten carbon atoms, with the proviso that no two
groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group.
[0053] The term "alkylene," as used herein, represents a saturated divalent hydrocarbon
group derived from a straight or branched chain saturated hydrocarbon by the removal
of two hydrogen atoms, and is exemplified by methylene, ethylene, isopropylene, and
the like.
[0054] The term "alkylsulfinyl," as used herein, represents an alkyl group attached to the
parent molecular group through an -S(O)- group. Exemplary unsubstituted alkylsulfinyl
groups are of from 1 to 6 carbons.
[0055] The term "alkylsulfonyl," as used herein, represents an alkyl group attached to the
parent molecular group through an -SO
2- group. Exemplary unsubstituted alkylsulfonyl groups are of from 1 to 6 carbons.
[0056] The term "alkylsulfinylalkyl," as used herein, represents an alkyl group, as defined
herein, substituted by an alkylsulfinyl group. Exemplary unsubstituted alkylsulfinylalkyl
groups are of from 2 to 12 carbons.
[0057] The term "alkylsulfonylalkyl," as used herein, represents an alkyl group, as defined
herein, substituted by an alkylsulfonyl group. Exemplary unsubstituted alkylsulfonylalkyl
groups are of from 2 to 12 carbons.
[0058] The term "alkynyl," as used herein, represents monovalent straight or branched chain
groups of from two to six carbon atoms containing a carbon-carbon triple bond and
is exemplified by ethynyl, 1-propynyl, and the like.
[0059] The term "amidine," as used herein, represents a -C(=NH)NH
2 group.
[0060] The term "amino," as used herein, represents an -NH
2 group.
[0061] The term "aminoalkyl," as used herein, represents an alkyl group, as defined herein,
substituted by an amino group.
[0062] The term "aryl," as used herein, represents a mono- or bicyclic carbocyclic ring
system having one or two aromatic rings and is exemplified by phenyl, naphthyl, 1,2-dihydronaphthyl,
1,2,3,4-tetrahydronaphthyl, fluorenyl, indanyl, indenyl, and the like, and may be
optionally substituted with one, two, three, four, or five substituents independently
selected from the group consisting of: (1) alkanoyl of one to six carbon atoms; (2)
alkyl of one to six carbon atoms; (3) alkoxy of one to six carbon atoms; (4) alkoxyalkyl,
where the alkyl and alkylene groups are independently of one to six carbon atoms;
(5) alkylsulfinyl of one to six carbon atoms; (6) alkylsulfinylalkyl, where the alkyl
and alkylene groups are independently of one to six carbon atoms; (7) alkylsulfonyl
of one to six carbon atoms; (8) alkylsulfonylalkyl, where the alkyl and alkylene groups
are independently of one to six carbon atoms; (9) aryl; (10) amino; (11) aminoalkyl
of one to six carbon atoms; (12) heteroaryl; (13) alkaryl, where the alkylene group
is of one to six carbon atoms; (14) aryloyl; (15) azido; (16) azidoalkyl of one to
six carbon atoms; (17) carboxaldehyde; (18) (carboxaldehyde)alkyl, where the alkylene
group is of one to six carbon atoms; (19) cycloalkyl of three to eight carbon atoms;
(20) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms and
the alkylene group is of one to ten carbon atoms; (21) halo; (22) haloalkyl of one
to six carbon atoms; (23) heterocyclyl; (24) (heterocyclyl)oxy; (25) (heterocyclyl)oyl;
(26) hydroxy; (27) hydroxyalkyl of one to six carbon atoms; (28) nitro; (29) nitroalkyl
of one to six carbon atoms; (30) N-protected amino; (31) N-protected aminoalkyl, where
the alkylene group is of one to six carbon atoms; (32) oxo; (33) thioalkoxy of one
to six carbon atoms; (34) thioalkoxyalkyl, where the alkyl and alkylene groups are
independently of one to six carbon atoms; (35) -(CH
2)
qCO
2R
A, where q is an integer of from zero to four, and R
A is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (36) -(CH
2)
qCONR
BR
C, where q is an integer of from zero to four and where R
B and R
C are independently selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(37) - (CH
2)
qSO
2R
D, where q is an integer of from zero to four and where R
D is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (38) -(CH
2)
qSO
2NR
ER
F, where q is an integer of from zero to four andwhere each of R
E and R
F is, independently, selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(39) -(CH
2)
qNR
GR
H, where q is an integer of from zero to four and where each of R
G and R
H is, independently, selected from the group consisting of (a) hydrogen; (b) an N-protecting
group; (c) alkyl of one to six carbon atoms; (d) alkenyl of two to six carbon atoms;
(e) alkynyl of two to six carbon atoms; (f) aryl; (g) alkaryl, where the alkylene
group is of one to six carbon atoms; (h) cycloalkyl of three to eight carbon atoms;
and (i) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms,
and the alkylene group is of one to ten carbon atoms, with the proviso that no two
groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group;
(40) thiol; (41) perfluoroalkyl; (42) perfluoroalkoxy; (43) aryloxy; (44) cycloalkoxy;
(45) cycloalkylalkoxy; and (46) arylalkoxy.
[0063] The term "arylalkoxy," as used herein, represents an alkaryl group attached to the
parent molecular group through an oxygen atom. Exemplary unsubstituted arylalkoxy
groups are of from 7 to 16 carbons.
[0064] The term "aryloxy" represents a chemical substituent of formula -OR', where R' is
an aryl group of 6 to 18 carbons, unless otherwise specified.
[0065] The terms "aryloyl" and "aroyl" as used interchangeably herein, represent an aryl
group that is attached to the parent molecular group through a carbonyl group. Exemplary
unsubstituted aryloyl groups are of 7 or 11 carbons.
[0066] The term "azido" represents an N
3 group, which can also be represented as N=N=N.
[0067] The term "azidoalkyl" represents an azido group attached to the parent molecular
group through an alkyl group.
[0068] The term "bridged heterocyclyl" represents a heterocyclic compound, as otherwise
described herein, having a bridged multicyclic structure in which one or more carbon
atoms and/or heteroatoms bridges two non-adjacent members of a monocyclic ring. An
exemplary bridged heterocyclyl group is a quinuclidinyl group.
[0069] The term "bridged alkheterocyclyl" represents a bridged heterocyclic compound, as
otherwise described herein, attached to the parent molecular group through an alkylene
group.
[0070] The term "carbonyl," as used herein, represents a C(O) group, which can also be represented
as C=O.
[0071] The term "carboxyaldehyde" represents a CHO group.
[0072] The term "carboxaldehydealkyl" represents a carboxyaldehyde group attached to the
parent molecular group through an alkylene group.
[0073] The term "cycloalkyl," as used herein represents a monovalent saturated or unsaturated
non-aromatic cyclic hydrocarbon group of from three to eight carbons, unless otherwise
specified, and is exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
cycloheptyl, bicyclo[2.2.1.]heptyl and the like. The cycloalkyl groups of this invention
can be optionally substituted with (1) alkanoyl of one to six carbon atoms; (2) alkyl
of one to six carbon atoms; (3) alkoxy of one to six carbon atoms; (4) alkoxyalkyl,
where the alkyl and alkylene groups are independently of one to six carbon atoms;
(5) alkylsulfinyl of one to six carbon atoms; (6) alkylsulfinylalkyl, where the alkyl
and alkylene groups are independently of one to six carbon atoms; (7) alkylsulfonyl
of one to six carbon atoms; (8) alkylsulfonylalkyl, where the alkyl and alkylene groups
are independently of one to six carbon atoms; (9) aryl; (10) amino; (11) aminoalkyl
of one to six carbon atoms; (12) heteroaryl; (13) alkaryl, where the alkylene group
is of one to six carbon atoms; (14) aryloyl; (15) azido; (16) azidoalkyl of one to
six carbon atoms; (17) carboxaldehyde; (18) (carboxaldehyde)alkyl, where the alkylene
group is of one to six carbon atoms; (19) cycloalkyl of three to eight carbon atoms;
(20) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms and
the alkylene group is of one to ten carbon atoms; (21) halo; (22) haloalkyl of one
to six carbon atoms; (23) heterocyclyl; (24) (heterocyclyl)oxy; (25) (heterocyclyl)oyl;
(26) hydroxy; (27) hydroxyalkyl of one to six carbon atoms; (28) nitro; (29) nitroalkyl
of one to six carbon atoms; (30) N-protected amino; (31) N-protected aminoalkyl, where
the alkylene group is of one to six carbon atoms; (32) oxo; (33) thioalkoxy of one
to six carbon atoms; (34) thioalkoxyalkyl, where the alkyl and alkylene groups are
independently of one to six carbon atoms; (35)-(CH
2)
qCO
2R
A, where q is an integer of from zero to four, and R
A is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (36) -(CH
2)
qCONR
BR
C, where q is an integer of from zero to four and where R
B and R
C are independently selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(37) - (CH
2)
qSO
2R
D, where q is an integer of from zero to four and where R
D is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (38) -(CH
2)
qSO
2NR
ER
F, where q is an integer of from zero to four andwhere each of R
E and R
F is, independently, selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(39) -(CH
2)
qNR
GR
H, where q is an integer of from zero to four and where each of R
G and R
H is, independently, selected from the group consisting of (a) hydrogen; (b) an N-protecting
group; (c) alkyl of one to six carbon atoms; (d) alkenyl of two to six carbon atoms;
(e) alkynyl of two to six carbon atoms; (f) aryl; (g) alkaryl, where the alkylene
group is of one to six carbon atoms; (h) cycloalkyl of three to eight carbon atoms;
and (i) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms,
and the alkylene group is of one to ten carbon atoms, with the proviso that no two
groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group;
(40) thiol; (41) perfluoroalkyl; (42) perfluoroalkoxy; (43) aryloxy; (44) cycloalkoxy;
(45) cycloalkylalkoxy; and (46) arylalkoxy.
[0074] The terms "cycloalkyloxy" or "cycloalkoxy", as used interchangeably herein, represent
a cycloalkyl group, as defined herein, attached to the parent molecular group through
an oxygen atom. Exemplary unsubstituted cycloalkyloxy groups are of from 3 to 8 carbons.
[0075] The term an "effective amount" or a "sufficient amount " of an agent, as used herein,
is that amount sufficient to effect beneficial or desired results, such as clinical
results, and, as such, an "effective amount" depends upon the context in which it
is being applied. For example, in the context of administering an agent that is an
inhibitor of NOS, an effective amount of an agent is, for example, an amount sufficient
to achieve a reduction in NOS activity as compared to the response obtained without
administration of the agent.
[0076] The terms "halide" or "halogen" or "Hal" or "halo," as used herein, represent bromine,
chlorine, iodine, or fluorine.
[0077] The term "heteroaryl," as used herein, represents that subset of heterocycles, as
defined herein, which are aromatic: i.e., they contain 4n+2 pi electrons within the
mono- or multicyclic ring system.
[0078] The terms "heterocycle" or "heterocyclyl," as used interchangeably herein represent
a 5-, 6- or 7-membered ring, unless otherwise specified, containing one, two, three,
or four heteroatoms independently selected from the group consisting of nitrogen,
oxygen and sulfur. The 5-membered ring has zero to two double bonds and the 6- and
7-membered rings have zero to three double bonds. The term "heterocycle" also includes
bicyclic, tricyclic and tetracyclic groups in which any of the above heterocyclic
rings is fused to one, two, or three rings independently selected from the group consisting
of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene
ring and another monocyclic heterocyclic ring, such as indolyl, quinolyl, isoquinolyl,
tetrahydroquinolyl, benzofuryl, benzothienyl and the like. Heterocyclics include pyrrolyl,
pyrrolinyl, pyrrolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl,
imidazolidinyl, pyridyl, piperidinyl, homopiperidinyl, pyrazinyl, piperazinyl, pyrimidinyl,
pyridazinyl, oxazolyl, oxazolidinyl, isoxazolyl, isoxazolidiniyl, morpholinyl, thiomorpholinyl,
thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl,
benzimidazolyl, benzothiazolyl, benzoxazolyl, furyl, thienyl, thiazolidinyl, isothiazolyl,
isoindazoyl, triazolyl, tetrazolyl, oxadiazolyl, uricyl, thiadiazolyl, pyrimidyl,
tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, dihydrothienyl, dihydroindolyl,
tetrahydroquinolyl, tetrahydroisoquinolyl, pyranyl, dihydropyranyl, dithiazolyl, benzofuranyl,
benzothienyl and the like. Heterocyclic groups also include compounds of the formula
where
F' is selected from the group consisting of -CH
2-, -CH
2O- and -O-, and G' is selected from the group consisting of -C(O)- and -(C(R')(R"))
v-, where each of R' and R" is, independently, selected from the group consisting of
hydrogen or alkyl of one to four carbon atoms, and v is one to three and includes
groups, such as 1,3-benzodioxolyl, 1,4-benzodioxanyl, and the like. Any of the heterocycle
groups mentioned herein may be optionally substituted with one, two, three, four or
five substituents independently selected from the group consisting of: (1) alkanoyl
of one to six carbon atoms; (2) alkyl of one to six carbon atoms; (3) alkoxy of one
to six carbon atoms; (4) alkoxyalkyl, where the alkyl and alkylene groups are independently
of one to six carbon atoms; (5) alkylsulfinyl of one to six carbon atoms; (6) alkylsulfinylalkyl,
where the alkyl and alkylene groups are independently of one to six carbon atoms;
(7) alkylsulfonyl of one to six carbon atoms; (8) alkylsulfonylalkyl, where the alkyl
and alkylene groups are independently of one to six carbon atoms; (9) aryl; (10) amino;
(11) aminoalkyl of one to six carbon atoms; (12) heteroaryl; (13) alkaryl, where the
alkylene group is of one to six carbon atoms; (14) aryloyl; (15) azido; (16) azidoalkyl
of one to six carbon atoms; (17) carboxaldehyde; (18) (carboxaldehyde)alkyl, where
the alkylene group is of one to six carbon atoms; (19) cycloalkyl of three to eight
carbon atoms; (20) alkcycloalkyl, where the cycloalkyl group is of three to eight
carbon atoms and the alkylene group is of one to ten carbon atoms; (21) halo; (22)
haloalkyl of one to six carbon atoms; (23) heterocyclyl; (24) (heterocyclyl)oxy; (25)
(heterocyclyl)oyl; (26) hydroxy; (27) hydroxyalkyl of one to six carbon atoms; (28)
nitro; (29) nitroalkyl of one to six carbon atoms; (30) N-protected amino; (31) N-protected
aminoalkyl, where the alkylene group is of one to six carbon atoms; (32) oxo; (33)
thioalkoxy of one to six carbon atoms; (34) thioalkoxyalkyl, where the alkyl and alkylene
groups are independently of one to six carbon atoms; (35) -(CH
2)
qCO
2R
A, where q is an integer of from zero to four, and R
A is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (36) -(CH
2)
qCONR
BR
C, where q is an integer of from zero to four and where R
B and R
C are independently selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(37) - (CH
2)
qSO
2R
D, where q is an integer of from zero to four and where R
D is selected from the group consisting of (a) alkyl, (b) aryl, and (c) alkaryl, where
the alkylene group is of one to six carbon atoms; (38) -(CH
2)
qSO
2NR
ER
F, where q is an integer of from zero to four andwhere each of R
E and R
F is, independently, selected from the group consisting of (a) hydrogen, (b) alkyl,
(c) aryl, and (d) alkaryl, where the alkylene group is of one to six carbon atoms;
(39) -(CH
2)
qNR
GR
H, where q is an integer of from zero to four and where each of R
G and R
H is, independently, selected from the group consisting of (a) hydrogen; (b) an N-protecting
group; (c) alkyl of one to six carbon atoms; (d) alkenyl of two to six carbon atoms;
(e) alkynyl of two to six carbon atoms; (f) aryl; (g) alkaryl, where the alkylene
group is of one to six carbon atoms; (h) cycloalkyl of three to eight carbon atoms;
and (i) alkcycloalkyl, where the cycloalkyl group is of three to eight carbon atoms,
and the alkylene group is of one to ten carbon atoms, with the proviso that no two
groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group;
(40) thiol; (41) perfluoroalkyl; (42) perfluoroalkoxy; (43) aryloxy; (44) cycloalkoxy;
(45) cycloalkylalkoxy; and (46) arylalkoxy.
[0079] The terms "heterocyclyloxy" and "(heterocycle)oxy," as used interchangeably herein,
represent a heterocycle group, as defined herein, attached to the parent molecular
group through an oxygen atom.
[0080] The terms "heterocyclyloyl" and "(heterocycle)oyl," as used interchangeably herein,
represent a heterocycle group, as defined herein, attached to the parent molecular
group through a carbonyl group.
[0081] The term "hydroxy" or "hydroxyl," as used herein, represents an -OH group.
[0082] The term "hydroxyalkyl," as used herein, represents an alkyl group, as defined herein,
substituted by one to three hydroxy groups, with the proviso that no more than one
hydroxy group may be attached to a single carbon atom of the alkyl group and is exemplified
by hydroxymethyl, dihydroxypropyl, and the like.
[0083] The terms "inhibit" or "suppress" or "reduce," as relates to a function or activity,
such as NOS activity, means to reduce the function or activity when compared to otherwise
same conditions except for a condition or parameter of interest, or alternatively,
as compared to another condition.
[0084] The term "N-protected amino," as used herein, refers to an amino group, as defined
herein, to which is attached an N-protecting or nitrogen-protecting group, as defined
herein.
[0085] The terms "N-protecting group" and "nitrogen protecting group," as used herein, represent
those groups intended to protect an amino group against undesirable reactions during
synthetic procedures. Commonly used N-protecting groups are disclosed in
Greene, "Protective Groups In Organic Synthesis," 3rd Edition (John Wiley & Sons,
New York, 1999), which is incorporated herein by reference. N-protecting groups include acyl, aroyl,
or carbamyl groups such as formyl, acetyl, propionyl, pivaloyl, t-butylacetyl, 2-chloroacetyl,
2-bromoacetyl, trifluoroacetyl, trichloroacetyl, phthalyl, o-nitrophenoxyacetyl, α-chlorobutyryl,
benzoyl, 4-chlorobenzoyl, 4-bromobenzoyl, 4-nitrobenzoyl, and chiral auxiliaries such
as protected or unprotected D, L or D, L-amino acids such as alanine, leucine, phenylalanine,
and the like; sulfonyl groups such as benzenesulfonyl, p-toluenesulfonyl, and the
like; carbamate forming groups such as benzyloxycarbonyl, p-chlorobenzyloxycarbonyl,
p-methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, 2-nitrobenzyloxycarbonyl, p-bromobenzyloxycarbonyl,
3,4-dimethoxybenzyloxycarbonyl, 3,5-dimethoxybenzyl oxycarbonyl, 2,4-dimethoxybenzyloxycarbonyl,
4-methoxybenzyloxycarbonyl, 2-nitro-4,5-dimethoxybenzyloxycarbonyl, 3,4,5-trimethoxybenzyloxycarbonyl,
1-(p-biphenylyl)-1-methylethoxycarbonyl, α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl,
benzhydryloxy carbonyl, t-butyloxycarbonyl, diisopropylmethoxycarbonyl, isopropyloxycarbonyl,
ethoxycarbonyl, methoxycarbonyl, allyloxycarbonyl, 2,2,2,-trichloroethoxycarbonyl,
phenoxycarbonyl, 4-nitrophenoxy carbonyl, fluorenyl-9-methoxycarbonyl, cyclopentyloxycarbonyl,
adamantyloxycarbonyl, cyclohexyloxycarbonyl, phenylthiocarbonyl, and the like, arylalkyl
groups such as benzyl, triphenylmethyl, benzyloxymethyl, and the like and silyl groups
such as trimethylsilyl, and the like. Preferred N-protecting groups are formyl, acetyl,
benzoyl, pivaloyl, t-butylacetyl, alanyl, phenylsulfonyl, benzyl, t-butyloxycarbonyl
(Boc), and benzyloxycarbonyl (Cbz).
[0086] The term "nitro," as used herein, represents an -NO
2 group.
[0087] The term "oxo" as used herein, represents =O.
[0088] The term "perfluoroalkyl," as used herein, represents an alkyl group, as defined
herein, where each hydrogen radical bound to the alkyl group has been replaced by
a fluoride radical. Perfluoroalkyl groups are exemplified by trifluoromethyl, pentafluoroethyl,
and the like.
[0089] The term "perfluoroalkoxy," as used herein, represents an alkoxy group, as defined
herein, where each hydrogen radical bound to the alkoxy group has been replaced by
a fluoride radical.
[0090] The term "pharmaceutically acceptable salt," as use herein, represents those salts
which are, within the scope of sound medical judgment, suitable for use in contact
with
the tissues of humans and animals without undue toxicity, irritation, allergic response
and the like and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically
acceptable salts are well known in the art. For example, S. M Berge et al. describe
pharmaceutically acceptable salts in detail in
J. Pharmaceutical Sciences 66:1-19, 1977. The salts can be prepared
in situ during the final isolation and purification of the compounds of the invention or
separately by reacting the free base group with a suitable organic acid. Representative
acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate,
benzoate, bisulfate, borate, butyrate, camphorate, camphersulfonate, citrate, cyclopentanepropionate,
digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate,
hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxyethanesulfonate,
lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate,
2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate,
pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate,
stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate,
valerate salts and the like. Representative alkali or alkaline earth metal salts include
sodium, lithium, potassium, calcium, magnesium and the like, as well as nontoxic ammonium,
quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium,
tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine
and the like.
[0091] The term "pharmaceutically acceptable prodrugs" as used herein, represents those
prodrugs of the compounds of the present invention which are, within the scope of
sound medical judgment, suitable for use in contact with with the tissues of humans
and animals with undue toxicity, irritation, allergic response, and the like, commensurate
with a reasonable benefit/risk ratio, and effective for their intended use, as well
as the zwitterionic forms, where possible, of the compounds of the invention.
[0092] The term "Ph" as used herein means phenyl.
[0093] The term "prodrug," as used herein, represents compounds which are rapidly transformed
in vivo to the parent compound of the above formula, for example, by hydrolysis in blood.
Prodrugs of the compounds of the invention may be conventional esters. Some common
esters which have been utilized as prodrugs are phenyl esters, aliphatic (C
8-C
24) esters, acyloxymethyl esters, carbamates, and amino acid esters. For example, a
compound of the invention that contains an OH group may be acylated at this position
in its prodrug form. A thorough discussion is provided in
T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S.
Symposium Series,
Edward B. Roche, ed., Bioreversible Carriers in Drug Design, American Pharmaceutical
Association and Pergamon Press, 1987, and
Judkins et al., Synthetic Communications 26(23):4351-4367, 1996, each of which is incorporated herein by reference.
[0094] Each of the terms "selectively inhibits nNOS" or "a selective nNOS inhibitor" refers
to a substance, such as, for example, a compound of the invention, that inhibits or
binds the nNOS isoform more effectively than the eNOS and/or iNOS isoform by an
in vitro assay, such as, for example, those assays described herein. Selective inhibition
can be expressed in terms of an IC
50 value, a K
i value, or the inverse of a percent inhibition value which is lower when the substance
is tested in an nNOS assay than when tested in an eNOS and/or iNOS assay. Preferably,
the IC
50 or K
i value is 2 times lower. More preferably, the IC
50 or K
i value is 5 times lower. Most preferably, the IC
50 or K
i value is 10, or even 50 times lower.
[0095] The term "solvate" as used herein means a compound of the invention wherein molecules
of a suitable solvent are incorporated in the crystal lattice. A suitable solvent
is physiologically tolerable at the dosage administered Examples of suitable solvents
are ethanol, water and the like. When water is the solvent, the molecule is referred
to as a "hydrate."
[0096] The term "spiroalkyl," as used herein, represents an alkylene diradical, both ends
of which are bonded to the same carbon atom of the parent group to form a spirocyclic
group.
[0097] The term "sulfonyl," as used herein, represents an -S(O)
2- group.
[0098] The term "thioalkheterocyclyl," as used herein, represents a thioalkoxy group substituted
with a heterocyclyl group.
[0099] The term "thioalkoxy," as used herein, represents an alkyl group attached to the
parent molecular group through a sulfur atom. Exemplary unsubstituted alkylthio groups
are of from 1 to 6 carbons.
[0100] The term "thiol" represents an -SH group.
[0101] As used herein, and as well understood in the art, "treatment" is an approach for
obtaining beneficial or desired results, such as clinical results. Beneficial or desired
results can include, but are not limited to, alleviation or amelioration of one or
more symptoms or conditions; diminishment of extent of disease, disorder, or condition;
stabilized (i.e. not worsening) state of disease, disorder, or condition; preventing
spread of disease, disorder, or condition; delay or slowing the progress of the disease,
disorder, or condition; amelioration or palliation of the disease, disorder, or condition;
and remission (whether partial or total), whether detectable or undetectable. "Treatment"
can also mean prolonging survival as compared to expected survival if not receiving
treatment "Palliating" a disease, disorder, or condition means that the extent and/or
undesirable clinical manifestations of the disease, disorder, or condition are lessened
and/or time course of the progression is slowed or lengthened, as compared to the
extent or time course in the absence of treatment. The term also includes prophylactic
treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0102]
Figure 1 is a bar graph showing the neuroprotective effect of compounds 9, 12, and 18 after NMDA challenge of rat cortical cells.
Figure 2 is a bar graph showing the neuroprotective effect of compounds 9, 12, and 18 after challenge of oxygen-glucose-deprived (OGD) rat hippocampal slices.
Figure 3 is a bar graph showing the effect of compound 12 on NMDA-mediated Ca2+ influx as measured using the fluorescent Ca2+ sensitive dye Fluo-4FF.
Figure 4 is a graph showing the effects of compound 12 on NMDA-mediated whole-cell currents in rat cortical neurons.
Figure 5 is a graph showing formalin-induced paw licking in mice after treatment with
(a) vehicle, (b) compound 12 at 5 mg/kg and 10 mg/kg, (c) treatment with the non-selective inhibitor 7-nitroindazole
(7-NI) at 2.5 mg/kg and 5 mg/kg.
Figure 6 is a bar graph showing the dose-related effect of compound 12 on the string score evaluated 1 hour after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; ns:non-significant versus vehicle-treated injured mice.
Figure 7 is a bar graph showing the dose-related effect of compound 12 on the Hall score evaluated 1 hour after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 8 is a bar graph showing the dose-related effect of compound 12 on the string score evaluated 4 hours after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; *P < 0.05 versus vehicle-treated injured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 9 is a bar graph showing the dose-related effect of compound 12 on the grip score evaluated 4 hours after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; *P < 0.05 versus vehicle-treated injured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 10 is a bar graph showing the dose-related effect of compound 12 on the Hall score evaluated 4 hours after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; *P < 0.05 versus vehicle-treated injured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 11 is a bar graph showing the dose-related effect of compound 12 on body temperature evaluated 1 hour after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 12 is a bar graph showing the dose-related effect of compound 12 on body temperature
evaluated 4 hours after traumatic brain injury in mice. Compound 12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; *P < 0.05 versus vehicle-treated injured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 13 is a bar graph showing the dose-related effect of compound 12 on body weight loss evaluated 24 hours after traumatic brain injury in mice. Compound
12 or vehicle was given s.c. 5 minutes post-injury. ††† P < 0.001 versus uninjured mice; *P < 0.05 versus vehicle-treated injured mice; ns: non-significant versus vehicle-treated injured mice.
Figure 14 shows the effects of compound 12 (50 µM) on population spike (PS) amplitude in hippocampal cells. Traces show PSs
recorded prior to (left), or 5 min after starting perfusion with 50 µM compound 12 (right). Results are typical of 3 experiments. Each trace is the average of 10 consecutively
recorded field potentials; 0.03 Hz stimulation.
Figure 15 shows the effects of compound 12 (50 µM) on population spike (PS) amplitude in hippocampal cells; control slices (left),
slices subjected to OGD (middle); and slices subjected OGD in 0.3 mM Ca2+. Each trace is the average of 10 consecutively recorded field potentials; 0.03 Hz
stimulation.
Figure 16 shows the effects of treatment with 0.3 M Ca2+, and NOS inhibitors 7-NI (100 µM) and compound 12. Either protection by low Ca2+ concentration (0.3 mM) or compound 12 (50 µM) shows preservation of population spike, while 7-NI (100 µM) treatment did
not preserve population spike in hippocampal slices.
Figure 17 shows the effects of 0.3M Ca2+ (PROT), 7-NI (100 µM) or compound 12 (50 µM) on the preservation of mitochondrial respiration in hippocampal slices after
10 min of OGD.
Figure 18 shows flow charts of the experimental designs used in the Chung Spinal Nerve
Ligation (SNL) model assays (tactile allodynia and thermal hyperalgesia) for neuropathic
pain.
Figure 19 shows the effect of 30 mg/kg i.p. administration of compounds 32(+) and 32(-) on the reversal of thermal hyperalgesia in rats after L5/L6 spinal nerve ligation
(Chung neuropathic pain model).
Figure 20 shows the effect of 30 mg/kg i.p. administration of compounds 32(+) and 32(-) on the reversal of tactile allodynia in rats after L5/L6 spinal nerve ligation
(Chung neuropathic pain model).
Figure 21 shows the dose response (3 mg/kg - 30 mg/kg) of compound 12 on the reversal of thermal hyperalgesia in rats after L5/L6 spinal nerve ligation
(Chung neuropathic pain model).
Figure 22 shows the dose response (3 mg/kg - 30 mg/kg) of compound 12 on the reversal of tactile hyperthesia in rats after L5/L6 spinal nerve ligation
(Chung neuropathic pain model).
Figure 23 is a bar graph showing the effects of various NOS inhibitors (i.v.) or Sumatriptan
succinate (s.c.) on the reversal of hindpaw allodynia in rats 2 hours after exposure
of the dura with an inflammatory soup.
DETAILED DESCRIPTION
[0103] The invention features substituted indole compounds having nitric oxide synthase
(NOS) inhibitory activity, pharmaceutical and diagnostic compositions containing them,
and their medical use, particularly as compounds for the treatment of stroke, reperfusion
injury, neurodegenerative disorders, head trauma, coronary artery bypass graft (CABG)
associated neurological damage, migraine, migraine with allodynia, neuropathic pain,
post-stroke pain, and chronic pain.
[0104] Exemplary 3,5-substituted indole compounds of the invention are provided in the following
table.
[0105] Exemplary 1,6-substituted indole compounds of the invention are provided in the following
table.
Methods of Preparing Compounds of the Invention
[0106] The compounds of the invention can be prepared by processes analogous to those established
in the art, for example, by the reaction sequences shown in Schemes 1-12.
[0107] A compound of formula IVa or IVb, where R
1, R
2, R
3, R
4, and R
7 are as defined elsewhere herein, can be prepared under standard alkylating conditions
by treating a compound of formula IIa or IIb, respectively, with a compound of formula
III, or a suitably protected derivative thereof, where R
1 is as defined above, with the exception that R
1 is not H, and "LG" is a leaving group, such as, for example, chloro, bromo, iodo,
or sulfonate (e.g., mesylate, tosylate, or triflate). Conditions to effect the alkylation
of a compound of formula IIa or IIb with a compound of formula III may include, for
example, heating a compound of formula II and a compound of formula III, with or without
a solvent, optionally in the presence of a suitable base (see Scheme 1).
[0108] Alternatively, production of a compound of formula IVa or IVb, or a suitably protected
derivative thereof, where R
2, R
3, R
4, and R
7 are as defined herein for a compound formula I and R
1 is (CH
2)
mX
1, where X
1 is
with R
1A, R
1B, R
1C, R
1D, Z
1, n1, p1, and q1 defined as for a compound of formula I involves the reaction of a
compound of formula Va or Vb, wherein m1 is as defined in for a compound of formula
I and LG is a suitable leaving group, such as, for example, chloro, bromo, iodo, or
sulfonate (e.g., mesylate, tosylate, or triflate), with compounds of formula VI, where
X
1 is as defined above, under standard alkylation conditions as shown in Scheme 2. Alternatively,
a compound of formula Va or Vb, where LG represents an aldehyde, ester, or acylchloride
group, may be reacted with a compound of formula VI. When LG is an aldehyde group,
standard reductive amination conditions may be employed using a suitable reducing
agent, such as NaBH
4, NaBH(OAc)
3, NaCNBH
4, and the like, in an alcoholic solvent, such as ethanol, to produce a compound of
formula VIIIa or VIIIb, respectively. The reductive amination may be performed in
one reaction or the imine resulting from mixing a compound of formula Va or Vb with
a compound of formula VI can be preformed
in situ, followed by sequential reduction with a suitable reducing agent When LG is an acyl
chloride or an ester group, preferably an active ester, such as, for example, pentafluorophenyl
ester or hydroxysuccinimide ester, the reaction of a compound of formula Va or Vb
with a compound of formula X
1-H, or a suitably protected derivative thereof, is followed by reduction of the resulting
amide using a suitable reducing agent, such as, for example, BH
3. Compounds of formulas Va or Vb may be prepared using standard methodologies, as
described in
WO 00/38677.
[0109] A compound of formula IVa or IVb, or a suitably protected derivative thereof, where
R
2, R
3, R
4, and R
7 are as defined herein for a compound formula I; LG is a suitable leaving group, such
as, for example, chloro, bromo, iodo, or a sulfonate (e.g., mesylate, tosylate, or
triflate); and X
3 is
where R
3A, R
3B, R
3C, R
3D, Z
3, n3, p3, and q3 are defined as for a compound of formula I can be prepared according
to Scheme 3, for example, by treating a compound of Formula IXa or IXb with oxalyl
chloride in a suitable solvent, such as, for example, ether, to produce a compound
of formula Xa or Xb, respectively. Subsequent reaction with amine X
3-H, followed by reduction with a reducing agent, such as LiAlH
4, according to standard procedures (
Blair et al., J. Med. Chem. 43:4701-4710, 2000;
Speeter and Anthony, J. Am. Chem. Soc. 76:6208-6210, 1954) produces a compound of formula XIa or XIb.
[0110] Using standard methodologies as described in the literature (
Russell et al., J. Med. Chem. 42:4981-5001, 1999;
Cooper et al., Bioorg. Med Chem. Lett. 11:1233-1236, 2001;
Sternfeld et al., J. Med. Chem. 42:677-690, 1999), a compound of formula XIVa, XIVb, XVa, or XVb, or a suitably protected derivative
thereof, where R
4 and R
7 are as defined elsewhere herein; X
3 is
where R
3A, R
3B, R
3C, R
3D, Z
3, n3, p3, and q3 are as defined elsewhere herein; X
2 is
where R
2A, 2
2B, R
2C, R
2D, Z
2, n2, p2, and q2 are as defined elsewhere herein; and LG is a suitable leaving group,
such as, for example, chloro, bromo, iodo, or triflate, can be prepared according
to Scheme 4 by treating amine X
3-H or X
2-H with a compound of formula XIIa or XIIb; or XIIIa or XIIIb, respectively, where
Y is a suitable leaving group, such as, for example, chloro, bromo, iodo, or sulfonate
(e.g., mesylate or tosylate). The Y group can be prepared from the appropriate alcohol
(i.e., Y = OH) using standard techniques.
[0111] A compound of formula XXIa or XXIb, where LG, R
4, R
7, Z
1, p1, and q1 are as defined elsewhere herein, can be prepared as shown in Scheme 5
by procedures analogous to those previously described (see, for example,
Coe et al., Tett. Lett. 37(34):6045-6048, 1996).
[0112] Accordingly, a compound of formula XXIIIa or XXIIIb, where LG, R
4, R
7, Z
3, p3, and q3 are as defined elsewhere herein can be prepared from a compound of formula
XXIIa or XXIIIb, as shown in Scheme 6, by procedures analogous to those previously
described (see, for example,
Perregaard et al., J. Med. Chem. 35:4813-4822, 1992;
Rowley et al., J. Med. Chem. 44:1603-1614, 2001).
[0113] A compound of formula XXVa or XXVb, where R
1, R
2, R
3, R
4, and R
7 are as defined in formula I, can be prepared by reduction of the nitro group of a
compound of formula XXIVa or XXIVb, respectively, or a suitably protected derivative,
under standard conditions as shown in Scheme 7. In one example, standard reduction
conditions include the use of SnCl
2 in a polar solvent, such as, for example, ethanol at refluxing temperatures. Alternatively,
a compound of formula XXVa or XXVb can be prepared by the hydrogenation of a compound
of formula XXIVa or XXIVb, respectively, using a suitable catalyst, such as palladium
on charcoal in ethanol or another solvent or combinations of solvents.
[0114] As shown in Scheme 8, a compound of formula XXVa or XXVb can also be prepared by
metal catalyzed amination of compounds of a compound of formula XXVIa or XXVIb, respectively,
where LG is chloro, bromo, iodo, or triflate (
Wolfe, et al. J. Org. Chem. 65:1158-1174, 2000) in the presence of a suitable ammonia equivalent, such as benzophenone imine, LiN(SiMe
3)
2, Ph
3SiNH
2, NaN(SiMe
3)
2, or lithium amide (
Huang and Buchwald, Org. Lett. 3(21):3417-3419, 2001). Examples of suitable metal catalysts include, for example, a palladium catalyst
coordinated to suitable ligands. Alternatively a suitable leaving group for palladium
catalyzed amination may be nonaflate (
Anderson, et al., J.Org.Chem. 68:9563-9573, 2003) or boronic acid (
Antilla and Buchwald, Org. Lett. 3(13):2077-2079, 2001) when the metal is a copper salt, such as Cu(II) acetate, in the presence of suitable
additives, such as 2,6-lutidine. A preferred leaving group is bromo in the presence
of palladium (0) or palladium (II) catalyst. Suitable palladium catalysts include
tris-dibenzylideneacetone dipalladium (Pd
2dba
3) and palladium acetate (PdOAc
2), preferably Pd
2dba
3. Suitable ligands for palladium can vary greatly and may include, for example, XantPhos,
BINAP, DPEphos, dppf, dppb, DPPP, (
o-biphenyl)-P(
t-Bu)
2, (
o-biphenyl)-P(Cy)
2, P(
t-Bu)3, P(Cy)
3, and others (
Huang and Buchwald, Org. Lett. 3(21):3417-3419, 2001). Preferably the ligand is P(t-Bu)
3. The Pd-catalyzed amination is performed in a suitable solvent, such as THF, dioxane,
toluene, xylene, DME, and the like, at temperatures between room temperature and reflux.
[0115] Compounds of formula XXIXa or XXIXb, where each of R
5A or R
6A is as defined elsewhere herein and Q is an aryl group (e.g., a phenyl group), a C
1 alkaryl group (e.g., a naphthylmethyl group), or an alkyl group (e.g., a methyl group)
are either commercially available or may be prepared by reacting a cyano compound
of formula XXVIIIa or XXVIIIb with thiol-containing compounds of formula XXVII. Other
examples of this transformation are described the art (see, for example,
Baati et al., Synlett 6:927-9, 1999;
EP 262873 1988,
Collins et al., J. Med. Chem. 41:15, 1998).
[0116] As shown in Scheme 10, a compound of formula XXXa or XXXb, where R
1, R
2, R
3, R
4, R
5A, R
6A, or R
7 are as defined elsewhere herein, can be prepared by reacting a compound of formula
XXVa or XXVb with a compound of formula XXIXa or XXIXb, respectively, where Q is defined
as above.
[0117] As shown in Scheme 11, a compound of formula XXXIIa or XXXIIb, where R
1, R
2, R
3, R
4, or R
7 are as defined elsewhere herein, can be prepared by reacting a compound of formula
XXVa or XXVb with a compound of formula XXXIa or XXXIb, respectively, where R
5B or R
6B are C
1-6alkyl, C
6-10aryl, C
1-4 alkaryl, C
2-9heterocyclyl, C
1-4 alkheterocyclyl, -C(O)C
1-6 alkyl, -C(O)C
6-10 aryl, - C(O)C
1-4 alkaryl, -C(O)C
2-9 heterocyclyl, or -C(O)C
1-4 alkheterocyclyl. The reaction can be performed in an inert solvent, such as tetrahydrofuran,
at ambient temperature or with heating. To prepare a compound of XXXIIIa or XXXIIIb,
a compound of formula XXXIIa or XXXIIb, where the thiourea is bonded to a carbonyl
moiety, is hydrolyzed under standard conditions, such as, for example, aqueous sodium
hydroxide in tetrahydrofuran.
[0118] As shown in Scheme 12, a compound of formula XXXIIIa or XXXIIIb may be further reacted
with an alkylating agent, such as, for example, R
5C-LG or R
6C-LG, where, R
5C or R
6C can be C
1-6 alkyl, C
1-4 alkaryl, or C
1-4 alkheterocyclyl and LG is a suitable leaving group, such as, for example, chloro,
bromo, iodo, or sulfonate (e.g., mesylate or tosylate).
[0119] In some cases the chemistries outlined above may have to be modified, for instance,
by the use of protective groups to prevent side reactions due to reactive groups,
such as reactive groups attached as substituents. This may be achieved by means of
conventional protecting groups as described in "
Protective Groups in Organic Chemistry," McOmie, Ed., Plenum Press, 1973 and in
Greene and Wuts, "Protective Groups in Organic Synthesis," John Wiley & Sons, 3rd
Edition, 1999.
[0120] The compounds of the invention, and intermediates in the preparation of the compounds
of the invention, may be isolated from their reaction mixtures and purified (if necessary)
using conventional techniques, including extraction, chromatography, distillation
and recrystallization.
[0121] The formation of a desired compound salt is achieved using standard techniques. For
example, the neutral compound is treated with an acid in a suitable solvent and the
formed salt is isolated by filtration, extraction, or any other suitable method.
[0122] The formation of solvates of the compounds of the invention will vary depending on
the compound and the solvate. In general, solvates are formed by dissolving the compound
in the appropriate solvent and isolating the solvate by cooling or adding an antisolvent.
The solvate is typically dried or azeotroped under ambient conditions.
[0123] Preparation of an optical isomer of a compound of the invention may be performed
by reaction of the appropriate optically active starting materials under reaction
conditions which will not cause racemization. Alternatively, the individual enantiomers
may be isolated by separation of a racemic mixture using standard techniques, such
as, for example, fractional crystallization or chiral HPLC.
[0124] A radiolabeled compound of the invention may be prepared using standard methods known
in the art. For example, tritium may be incorporated into a compound of the invention
using standard techniques, such as, for example, by hydrogenation of a suitable precursor
to a compound of the invention using tritium gas and a catalyst Alternatively, a compound
of the invention containing radioactive iodine may be prepared from the corresponding
trialkyltin (suitably trimethyltin) derivative using standard iodination conditions,
such as [
125I] sodium iodide in the presence of chloramine-T in a suitable solvent, such as dimethylformamide.
The trialkyltin compound may be prepared from the corresponding non-radioactive halo,
suitably iodo, compound using standard palladium-catalyzed stannylation conditions,
such as, for example, hexamethylditin in the presence of tetrakis(triphenylphosphine)
palladium (0) in an inert solvent, such as dioxane, and at elevated temperatures,
suitably 50-100°C.
Pharmaceutical Uses
[0125] The present invention features all uses for a compound of formula I, including their
use in therapeutic methods, whether alone or in combination with another therapeutic
substance, their use in compositions for inhibiting NOS activity, their use in diagnostic
assays, and their use as research tools.
[0126] The compounds of the invention have useful NOS inhibiting activity, and therefore
are useful for treating, or reducing the risk of, diseases or conditions that are
ameliorated by a reduction in NOS activity. Such diseases or conditions include those
in which the synthesis or oversynthesis of nitric oxide plays a contributory part.
[0127] Accordingly, the present invention features a medicament containing an effective
amount of the compound of the invention for treating a condition in a mammal, in particular
a human, caused by the action of nitric oxide synthase (NO5). Such diseases or conditions
include, for example, migraine headache with and without aura, neuropathic pain, chronic
tension type headache headache, chronic pain, acute spinal cord injury, diabetic neuropathy,
diabetic nephropathy, an inflammatory disease, stroke, reperfusion injury, head trauma,
cardiogenic shock, CABG associated neurological damage, HCA, AIDS associated dementia,
neurotoxicity, Parkinson's disease, Alzheimer's disease, ALS, Huntington's disease,
multiple sclerosis, metamphetamine-induced neurotoxicity, drug addiction, morphine/opioid
induced tolerance, dependence, hyperalgesia or withdrawal, ethanol tolerance, dependence,
or withdrawal, epilepsy, anxiety, depression, attention deficit hyperactivity disorder,
and psychosis. In particular, 3,5-substituted indoles of the invention are particularly
useful to treat migraine, with or without aura and chronic tension type headache (CTTH)
and for migraine prophylaxis.
[0128] Following is a summary and a basis for the link between NOS inhibition and some of
these conditions.
Migraine
[0129] The first observation by Asciano Sobrero in 1847 that small quantities of nitroglycerine,
an NO releasing agent, causes severe headache lead to the nitric oxide hypothesis
of migraine (
Olesen et al., Cephalagia 15:94-100, 1995). Serotonergic 5HT
1D/1B agonists, such as sumatriptan, which are used clinically in the treatment of migraine,
are known to prevent the cortical spreading depression in the lissencephalic and gyrencephalic
brain during migraine attack, a process resulting in widespread release of NO. Indeed,
it has been shown that sumatriptan modifies the artificially enhanced cortical NO
levels following infusion of glyceryl trinitate in rats (
Read et al., Brain Res. 847:1-8, 1999;
ibid, 870(1-2):44-53, 2000). In a human randomized double-blinded clinical trial for migraine, a 67% response
rate after single i.v. administration of L-N
G methylarginine hydrochloride (L-NMMA, an NOS inhibitor) was observed. The effect
was not attributed to a simple vasoconstriction since no effect was observed on transcranial
doppler determined velocity in the middle cerbral artery (
Lassen et al., Lancet 349:401-402, 1997). In an open pilot study using the NO scavenger hydroxycobalamin, a reduction in
the frequency of migraine attack of 50% was observed in 53% of the patients and a
reduction in the total duration of migraine attacks was also observed (
van der Kuy et al., Cephalgia 22(7):513-519, 2002).
Migraine with Allodynia
[0130] Clinical studies have shown that as many as 75% of patients develop cutaneous allodynia
(exaggerated skin sensitivity) during migraine attacks and that its development during
migraine is detrimental to the anti-migraine action of triptan 5HT
1B/1D agonists (
Burstein et al., Ann. Neurol. 47:614-624, 2000;
Burstein et al., Brain, 123:1703-1709, 2000). While the early administration of triptans such as sumatriptan can terminate migraine
pain, late sumatriptan intervention is unable to terminate migraine pain or reverse
the exaggerated skin sensitivity in migraine patients already associated with allodynia
(
Burstein et al., Ann. Neurol. DOI:10.1002/ana.10785, 2003;
Burstein and Jakubowski, Ann. Neurol., 55:27-36, 2004). The development of peripheral and central sensitization correlates with the clinical
manifestations of migraine. In migraine patients, throbbing occurs 5-20 minutes after
the onset of headache, whereas cutaneous allodynia starts between 20-120 minutes (
Burstein et al., Brain, 123:1703-1709, 2000). In the rat, experimentally induced peripheral sensitization of meningeal nociceptors
occurs within 5-20 minutes after applying an inflammatory soup (I.S.) to the dura
(
Levy and Strassman, J. Physiol., 538:483-493, 2002), whereas central sensitization of trigeminovascular neurons develops between 20-120
minutes (
Burstein et al., J. Neurophysiol. 79:964-982, 1998) after I.S. administration. Parallel effects on the early or late administration
of antimigraine triptans like sumatriptan on the development of central sensitization
have been demonstrated in the rat (Burstein and Jakubowski,
vide supra). Thus, early but not late sumatriptan prevents the long-term increase in I.S.-induced
spontaneous activity seen in central trigeminovascular neurons (a clinical correlate
of migraine pain intensity). In addition, late sumatriptan intervention in rats did
not prevent I.S.-induced neuronal sensitivity to mechanical stimulation at the periorbital
skin, nor decreased the threshold to heat (a clinical correlate of patients with mechanical
and thermal allodynia in the periorbital area). In contrast, early sumatriptan prevented
I.S. from inducing both thermal and mechanical hypersensitivity. After the development
of central sensitization, late sumatriptan intervention reverses the enlargement of
dural receptive fields and increases in sensitivity to dural indentation (a clinical
correlate of pain throbbing exacerbated by bending over) while early intervention
prevents its development.
[0131] Previous studies on migraine compounds such as sumatriptan (
Kaube et al., Br. J. Pharmacol. 109:788-792, 1993), zolmitriptan (
Goadsby et al., Pain 67:355-359, 1996), naratriptan (
Goadsby et al., Br. J. Pharmacol., 328:37-40, 1997), rizatriptan (
Cumberbatch et al., Eur. J Pharmacol., 362:43-46, 1998), or L-471-604 (
Cumberbatch et al., Br. J. Pharmacol. 126:1478-1486, 1999) examined their effects on nonsensitized central trigeminovascular neurons (under
normal conditions) and thus do not reflect on their effects under the pathophysiolocal
conditions of migraine. While triptans are effective in terminating the throbbing
of migraine whether administered early or late, the peripheral action of sumatriptan
is unable to terminate migraine pain with allodynia following late intervention via
the effects of central sensitization oftrigeminovascular neurons. The limitations
of triptans suggest that improvement in the treatment of migraine pain can be achieved
by utilizing drugs that can abort ongoing central sensitization, such as the compounds
of the present invention.
[0132] It has been shown that systemic nitroglycerin increases nNOS levels and c-Fos-immunoreactive
neurons (a marker neuronal activation) in rat trigeminal nucleus caudalis after 4
hours, suggesting NO likely mediates central sensitization of trigeminal neurons (
Pardutz et al., Neuroreport 11(14):3071-3075, 2000). In addition, L-NAME can attenuate Fos expression in the trigeminal nucleus caudalis
after prolonged (2 hrs) electrical stimulation of the superior sagittal sinus (
Hoskin et al. Neurosci. Lett. 266(3):173-6, 1999). Taken together with ability of NOS inhibitors to abort acute migraine attack (
Lassen et al., Cephalalgia 18(1):27-32, 1998), the compounds of the invention, alone or in combination with other antinociceptive
agents, represent excellent candidate therapeutics for aborting migraine in patients
after the development of allodynia.
Chronic Headache (CTTH)
[0133] NO contributes to the sensory transmission in the peripheral (
Aley et al., J. Neurosci. 1:7008-7014, 1998) and central nervous system (
Meller and Gebhart, Pain 52:127-136, 1993). Substantial experimental evidence indicates that central sensitization, generated
by prolonged nociceptive input from the periphery, increases excitability of neurons
in the CNS and is caused by, or associated with, an increase in NOS activation and
NO synthesis (
Bendtsen, Cephalagia 20:486-508, 2000;
Woolf and Salter, Science 288:1765-1769, 2000). It has been shown that experimental infusion of the NO donor, glyceryl trinitrate,
induces headache in patients. In a double-blinded study, patients with chronic tension-type
headache receiving L-NMMA (an NOS inhibitor) had a significant reduction in headache
intensity (
Ashina and Bendtsen, J. Headache Pain 2:21-24, 2001;
Ashina et al., Lancet 243(9149):287-9, 1999). Thus the NOS inhibitors of the present invention may be useful for the treatment
of chronic tension-type headache.
Acute Spinal Cord Injury, Chronic or Neuropathic Pain
[0134] In humans, NO evokes pain on intracutaneous injection (
Holthusen and Arndt, Neurosci. Lett. 165:71-74, 1994), thus showing a direct involvement of NO in pain. Furthurmore, NOS inhibitors have
little or no effect on nociceptive transmission under normal conditions (
Meller and Gebhart, Pain 52:127-136, 1993). NO is involved in the transmission and modulation of nociceptive information at
the periphery, spinal cord and supraspinal level (
Duarte et al., Eur. J. Pharmacol. 217:225-227, 1992;
Haley et al., Neuroscience 31:251-258, 1992). Lesions or dysfunctions in the CNS may lead to the development of chronic pain
symptoms, known as central pain, and includes spontaneous pain, hyperalgesia, and
mechanical and cold allodynia (
Pagni, Textbook of Pain, Churchill Livingstone, Edinburgh, 1989, pp. 634-655;
Tasker In: The Management of Pain, pp. 264-283, J.J. Bonica (Ed.), Lea and Febiger,
Philadelphia, PA, 1990;
Casey, Pain and Central Nervous System Disease: The Central Pain Syndromes, pp. 1-11
K.L. Casey (Ed.), Raven Press, New York, 1991). It has been demonstrated that systemic administration (i.p.) of the NOS inhibitors
7-NI and L-NAME relieve chronic allodynia-like symptoms in rats with spinal cord injury
(
Hao and Xu, Pain 66:313-319, 1996). The effects of 7-NI were not associated with a significant sedative effect and
were reversed by L-arginine (NO precursor). The maintenance of thermal hyperalgesia
is believed to be mediated by nitric oxide in the lumbar spinal cord and can be blocked
by intrathecal administration of a nitric oxide synthase inhibitor like L-NAME or
soluble guanylate cyclase inhibitor methylene blue (
Neuroscience 50(1):7-10, 1992). Thus the NOS inhibitors of the present invention may be useful for the treatment
of chronic or neuropathic pain.
Diabetic Neuropathy
[0135] The endogenous polyamine metabolite agmatine is a metabolite of arginine that is
both an NOS inhibitor and N-methyl-D-aspartate (NMDA) channel antagonist. Agmatine
is effective in both the spinal nerve ligation (SNL) model of neuropathic pain as
well as the streptozotocin model of diabetic neuropathy (
Karadag et al., Neurosci. Lett. 339(1):88-90, 2003). Thus compounds possessing NOS inhibitory activity, such as, for example, a compound
of formula I, a combination of an NOS inhibitor and an NMDA antagonist should be effective
in treating diabetic neuropathy and other neuropathic pain conditions.
Inflammatory Diseases and Neuroinflammation
[0136] LPS, a well known pharmacological tool, induces inflammation in many tissues and
activates NFκB in all brain regions when administered intravenously. It also activates
pro-inflammatory genes when injected locally into the striaitum (
Stem et al., J. Neuroimmunology, 109:245-260, 2000). Recently it has been shown that both the NMDA receptor antagonist MK801 and the
brain selective nNOS inhibitor 7-NI both reduce NFκB activation in the brain and thus
reveal a clear role for glutamate and NO pathway in neuroinflammation (
Glezer et al., Neuropharmacology 45(8):1120-1129,2003). Thus, the administration, of a compound of the invention, either alone or in combination
with an NMDA antagonist, should be effective in treating diseases arising from neuroinflammation.
Stroke and Reperfusion Injury
[0137] The role of NO in cerebral ischemia can be protective or destructive depending on
the stage of evolution of the ischemic process and on the cellular compartment producing
NO (
Dalkara et al., Brain Pathology 4:49, 1994). While the NO produced by eNOS is likely beneficial by acting as a vasodilator to
improve blood flow to the affected area (
Huang et al., J.Cereb. Blood Flow Metab. 16:981, 1996), NO produced by nNOS contributes to the initial metabolic deterioration of the ischemic
penumbra, resulting in larger infarcts (
Hara et al., J. Cereb. Blood Flow Metab. 16:605, 1996). The metabolic derangement that occurs during ischemia and subsequent reperfusion
results in the expression and release of several cytokines that activate iNOS in several
cell types including some of the central nervous system. NO can be produced at cytotoxic
levels by iNOS, and increased levels of iNOS contribute to progressive tissue damage
in the penumbra, leading to larger infarcts (
Parmentier et al., Br. J. Pharmacol. 127:546, 1999). Inhibition of i-NOS has been shown to ameliorate cerebral ischemic damage in rats
(
Am. J. Physiol. 268:R286, 1995).
[0138] It has been shown that a synergistic neuroprotective effect is observed upon the
combined administration of an NMDA antagonist (eg MK-801 or LY29355 8) with nNOS selective
inhibitors (7-NI or ARL17477) in global cerebral ischemia (
Hicks et al., Eur. J. Pharmacol. 381:113-119, 1999). Thus the compounds of the invention, administered either alone or in combination
with NMDA antagonists, or compounds possessing mixed nNOS/NMDA activity, may be effective
in treating conditions of stroke and other neurodegenerative disorders.
Complications Resulting from Coronary Artery Bypass Surgery
[0139] Cerebral damage and cognitive dysfunction still remains as a major complication of
patients undergoing coronary artery bypass surgery (CABG) (
Roch et al., N. Eng. J. Med. 335:1857-1864, 1996;
Shaw et al., Q. J. Med. 58:59-68, 1986). This cerebral impairment following surgery is a result of ischemia from preoperative
cerebral microembolism. In a randomized trial of the NMDA antagonist remacemide, patients
showed a significant overall postoperative improvement in learning ability in addition
to reduced deficits (
Arrowsmith et al., Stroke 29:2357-2362, 1998). Given the involvement of excitotoxicity produced by excessive release of glutamate
and calcium influx, it is expected that a neuroprotective agent, such as a compound
of the invention or an NMDA antagonist, either alone or in combination, may have a
beneficial effect improving neurological outcomes after CABG.
AIDS-associated Dementia
[0140] HIV-1 infection can give rise to dementia. The HIV-1 coat protein gp-120 kills neurons
in primary cortical cultures at low picomolar levels and requires external glutamate
and calcium (Dawson et al., 90(8):3256-3259, 1993). This toxicity can be attenuated
by administration of a compound of the invention, either alone or in combination with
another therapeutic agent, such as, for example, an NMDA antagonist.
[0141] Examples of NMDA antagonist useful for any of the combinations of the invention include
aptiganel; besonprodil; budipine; conantokin G; delucemine; dexanabinol; felbamate;
fluorofelbamate; gacyclidine; glycine; ipenoxazone; kaitocephalin; lanicemine; licostinel;
midafotel; milnacipran; neramexane; orphenadrine; remacemide; topiramate; (α
R)-α-amino-5-chloro-1-(phosphonomethyl)-1H-benzimidazole-2-propanoic acid; 1-aminocyclopentane-carboxylic
acid; [5-(aminomethyl)-2-[[[(5
S)-9-chloro-2,3,6,7-tetrahydro-2,3-dioxo-1H-,5H-pyrido[1,2,3-de]quinoxalin-5-yl]acetyl]amino]phenoxy]-acetic
acid; α-amino-2-(2-phosphonoethyl)-cyclohexanepropanoic acid; α-amino-4-(phosphonomethyl)-benzeneacetic
acid; (3E)-2-amino-4-(phosphonomethyl)-3-heptenoic acid; 3-[(1E)-2-carboxy-2-phenylethenyl]-4,6-dichloro-1H-indole-2-carboxylic
acid; 8-chloro-2,3-dihydropyridazino[4,5-b]quinoline-1,4-dione 5-oxide salt with 2-hydroxy-N,N,N-trimethyl-ethanaminium;
N-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-(methylthio)phenyl]-guanidine; N'-[2-chloro-5-(methylthio)phenyl]-N-methyl-N-[3-[(
R)-methylsulfinyl]phenyl]-guanidine; 6-chloro-2,3,4,9-tetrahydro-9-methyl-2,3-dioxo-1H-indeno[1,2-b]pyrazine-9-acetic
acid; 7-chlorothiokynurenic acid; (3
S,4a
R,6
S,8a
R)-decahydro-6-(phosphonomethyl)-3-isoquinolinecarboxylic acid; (-)-6,7-dichloro-1,4-dihydro-5-[3-(methoaymethyl)-5-(3-pyridinyl)-4-H-1,2,4-triazol-4-yl]-2,3-quinoxalinedione;
4,6-dichloro-3-[(E)-(2-oxo-1-phenyl-3-pyrrolidinylidene)methyl]-1H-indole-2-carboxylic
acid; (2
R,4
S)-rel-5,7-dichloro-1,2,3,4-tetrahydro-4-[[(phenylamino)carbonyl]amino]-2-quinolinecarboxylic
acid; (3
R,4
S)-rel-3,4-dihydro-3-[4-hydroxy-4-(phenylmethyl)-1-piperidinyl-]-2H-1-benzopyran-4,7-diol;
2-[(2,3-dihydro-1H-inden-2-yl)amino]-acetamide; 1,4-dihydro-6-methyl-5-[(methylamino)methyl]-7-nitro-2,3-quinoxalinedione;
[2-(8,9-dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)ethyl]-phosphonic acid; (2
R,6
S)-1,2,3,4,5,6-hexahydro-3-[(2S)-2-methoxypropyl]-6,11,11-tmethyl-2,6-methano-3-benzazocin-9-ol;
2-hydroxy-5-[[(pentaffuorophenyl)methyl]amino]-benzoic acid; 1-[2-(4-hydroxyphenoxy)ethyl]-4-[(4-methylphenyl)methyl]-4-piperidinol;
1-[4-(1H-imidazol-4-yl)-3-butynyl]-4-(phenylmethyl)-piperidine; 2-methyl-6-(phenylethynyl)-pyridine;
3-(phosphonomethyl)-L-phenylalanine; and 3,6,7-tetrahydro-2,3-dioxo-N-phenyl-1H,5H-pyrido[1,2,3-de]quinoxaline-5-acetamide
or those described in
U.S. Patent Nos. 6,071,966;
6,034,134; and
5,061,703.
Cardiogenic Shock
[0142] Cardiogenic shock (CS) is the leading cause of death for patients with acute myocardial
infarction that is consistent with increased levels of NO and inflammatory cytokines.
High levels of NO and peroxynitrite have many effects, including a direct inhibition
on myocardial contractability, suppression of mitochondrial respiration in myocardium,
alteration in glucose metabolism, reduced catacholamine responsivity, and induction
of systemic vasodilation (
Hochman, Circulation 107:2998, 2003). In a clinical study in 11 patients with persistent shock, administration of the
NOS inhibitor L-NMMA resulted in increases in urine output and blood pressure and
survival rate of 72% up to 30 days (
Cotter et al., Circulation 101:1258-1361, 2000). In a randomized trial of 30 patients, it was reported that L-NAME reduced patient
mortality from 67% to 27% (
Cotter et al., Eur. Heart. J. 24(14):1287-95, 2003). Similarly, administration of a compound of the invention, either alone or in combination
with another therapeutic agent, may be useful for the treatment of cardiogenic shock.
Anxiety and Depression
[0143] Recent studies of rats and mice in the forced swimming test (FST) indicate that NOS
inhibitors have antidepressant activity in mice (
Harkin et al. Eur. J. Pharm. 372:207-213, 1999) and that their effect is mediated by a serotonin dependent mechanism (
Harkin et al., Neuropharmacology 44(5):616-623, 1993). 7-NI demonstrates anxiolytic activity in the rat plus-maze test (
Yildiz et al., Pharmacology, Biochemistry and Behavior 65:199 202, 2000), whereas the selective nNOS inhibitor TRIM is effective in both the FST model of
depression and anxiety in the light-dark compartment test (
Volke et al., Behavioral Brain Research 140(1-2):141-7, 2003). Administration of a compound of the invention to an afflicted individual, either
alone or in combination with another therapeutic agent, such as, for example, an antidepressant,
may be useful for the treatment of anxiety or depression.
Attention Deficit Hyperactivity Disorder
[0144] Non-selective attention (NSA) to environmental stimuli in Spontaneously Hypertensive
(SHR) and Naples Low-Excitability (NHE) rats has been used as an animal model of Attention-Deficit
Hyperactivity Disorder (ADHD) (
Aspide et al., Behav. Brain Res. 95(1):23-33, 1998). These genetically altered animals show increased episodes of rearing that have
a shorter duration than observed in normal animals. A single injection of L-NAME at
10 mg/kg produced an increase in rearing duration. Similarly, using the more neuronally
selective 7-NINA, an increase in the rearing duration was observed after rapid administration
(i.p.), while a slow release single release dose or a slow multiple release dose (s.c.
in DMSO) resulted in the opposite effect. Thus, administration of a compound of the
invention may be useful for the treatment of ADHD.
Psychosis
[0145] Phencyclidine (PCP) is a non-competitive NMDA channel blocker that produces behavioral
side effects in human and mammals consistent with those observed in patients with
psychosis. In two animal models of psychosis, the nNOS selective inhibitor AR-R17477
antagonized PCP-induced hyperlocomotion and PCP-induced deficit in prepulse inhibition
of the acoustic response startle (
Johansson et al., Pharmacol. Toxicol. 84(5):226-33, 1999). These results suggest the involvement of nNOS in psychosis. Therefore, administration
of a compound of the invention to an afflicted individual may be useful for the treatment
of this or related diseases or disorders.
Head Trauma
[0146] The mechanism of neurological damage in patients with head trauma parallels that
of stroke and is related to excitotoxic calcium influx from excessive glutamate release,
oxidative stress and free radical production from mitochondrial dysfunction and inflammation
(
Drug & Market Development 9(3):60-63, 1998). Animals treated with nitric oxide synthase inhibitors, such as 7-NI and 3-bromo-7-nitroindazole,
have shown an improvement in neurological deficits after experimental traumatic brain
injury (TBI) (
Mesenge et al., J. Neurotrauma 13:209-14, 1996). Administration of a compound of the invention to an afflicted individual may also
be useful for the treatment of neurological damage in head trauma injuries.
Hypothermic Cardiac Arrest
[0147] Hypothermic cardiac arrest (HCA) is a technique used to protect from ischemic damage
during cardiac surgery when the brain is sensitive to damage during the period of
blood flow interruption. Various neuroprotective agents have been used as adjunct
agents during HCA and reducing nitric oxide production during HCA is predicted to
result in improvements in neurological function. This is based on previous studies
that showed glutamate excitotoxicity plays a role in HCA-induced neurologic damage
(
Redmond et al., J. Thorac. Cardiovasc. Surg. 107:776-87, 1994;
Redmond et al., Ann. Thorac. Surg. 59:579-84, 1995) and that NO mediates glutamate excitotoxicity (
Dawson and Snyder, J. Neurosci. 14:5147-59, 1994). In a study of 32 dogs undergoing 2 hours of HCA at 18°C, a neuronal NOS inhibitor
was shown to reduce cerebral NO production, significantly reduce neuronal necrosis,
and resulted in superior neurologic function relative to controls (
Tseng et al., Ann. Thorac. Surg. 67:65-71, 1999). Administration of a compound of the invention may also be useful for protecting
patients from ischemic damage during cardiac surgery.
Neurotoxicity and Neurodegenerative Diseases
[0148] Mitochondrial dysfunction, glutamate excitotoxicity, and free radical induced oxidative
damage appear to be the underlying pathogenesis of many neurodegenerative diseases,
including amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), Alzheimer's
disease (AD), and Huntington's disease (HD) (
Schulz et al., Mol. Cell. Biochem. 174(1-2):193-197, 1997;
Beal, Ann. Neurol. 38:357-366, 1995), and NO is a primary mediator in these mechanisms. For example, it was shown by
Dawson et al., in PNAS 88(14):6368-6371, 1991, that NOS inhibitors like 7-NI and L-NAME prevent neurotoxicity elicited by N-methyl-D-aspartate
and related excitatory amino acids.
(a) Parkinson's Disease
[0149] Studies have also shown that NO plays an important role in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
(MPTP) neurotoxicity, a commonly used animal model of Parkinson's disease (
Matthews et al., Neurobiology of Disease 4:114-121, 1997). MPTP is converted to MPP+ by MAO-B and is rapidly taken up by the dopamine transporter
into the mitochondria of dopamine containing neurons with subsequent activation of
nNOS resulting in neuronal death. Mutant mice lacking the nNOS gene, but not the eNOS
gene, have reduced lesions in the substantia nigra after MPP+ injection into the striatum.
In primate studies, 7-NI exerts a profound neuroprotective and antiparkinsonium effect
after MPTP challenge (
Hantraye et al., Nature Med. 2:1017-1021, 1996) as did the nonspecific inhibitor L-NAME (
T.S. Smith et al. Neuroreport 1994, 5, 2598-2600).
(b) Alzheimer's Disease (AD)
[0150] The pathology of AD is associated with β-amyloid plaques infiltrated with activated
microglia and astrocytes. When cultured rat microglia are exposed to beta-amyloid,
there is a prominent microglial release of nitric oxide, especially in the presence
of gamma-interferon (
Goodwin et al., Brain Research 692(1-2):207-14, 1995). In cortical neuronal cultures, treatment with nitric oxide synthase inhibitors
provides neuroprotection against toxicity elicited by human beta-amyloid (
Resink et al., Neurosci. Abstr. 21:1010, 1995). Consistent with the glutamate hypothesis of excitoxicity in neurodegerative disorders,
the weak NMDA antagonist amantadine increases the life expectancy of PD patients (
Uitti et al., Neurology 46(6):1551-6, 1996). In a preliminary, placebo-controlled study of patients with vascular- or Alzheimer's-type
dementia, the NMDA antagonist memantine was associated with improved Clinical Global
Impression of Change and Behavioral Rating Scale for Geriatric Patients scores (
Winblad and Poritis, Int. J. Geriatr. Psychiatry 14:135-46, 1999).
(c) Amyotrophic Lateral Sclerosis
[0151] Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized
by selective motor neuronal death. Accumulating evidence suggests that the pathogenesis
of ALS is the insufficient clearance of glutamate through the glutamate transporter,
and the specific distribution of Ca
2+-permeable AMPA receptors in spinal motor neurons, indicates a glutamate-induced neurotoxicity.
Increased nNOS immunoreactivity is found in the spinal cords (
Sasaki et al., Acta Neuropathol. (Berl) 101(4):351-7, 2001) and glial cells (
Anneser et al., Exp. Neurol. 171(2):418-21, 2001) ofALS patients, implicating NO as an important factor in the pathogenesis of ALS.
(d) Huntington's Disease
[0152] The pathogenesis of Huntington's disease (HD) arising from a mutation in the Htt
protein is linked to excitotoxicity, oxidative stress and apoptosis, in all of which
excessive NO has a clear role (
Peterson et al., Exp. Neurol. 157:1-18, 1999). Oxidative damage is one of the major consequences of defects in energy metabolism
and is present in HD models after injection of excitotoxins and mitochondrial inhibitors
(
A. Petersen et al., Exp. Neurol. 157:1-18, 1999). This mitochrondrial dysfunction is associated with the selective and progressive
neuronal loss in HD (
Brown et al., Ann. Neurol. 41:646-653, 1997). NO can directly impair the mitochondrial respiratory chain complex IV (
Calabrese et al., Neurochem. Res. 25:1215-41, 2000). Striatal medium spiny neurons appear to be the primary target for the generation
of motor dysfunction in HD. Hyperphosphorylation and activation of NMDA receptors
on these neurons likely participates in the generation of motor dysfunction. It has
been shown clinically that the NMDA antagonist amantadine improve choreiform dyskinesias
in HD (
Verhagen Metman et al., Neurology 59:694-699, 2002). Given the role of nNOS in NMDA mediated neurotoxicity, it is expected that nNOS
inhibitors, especially those with mixed nNOS/NMDA, or combinations of drugs with nNOS
and NMDA activity will also be useful in ameliorating the effects and or progression
of HD. For example, pretreatment of rats with 7-nitroindazole attenuates the striatal
lesions elicited by stereotaxic injections of malonate, an injury that leads to a
condition resembling Huntington's disease (
Hobbs et. al., Ann. Rev. Pharm. Tox. 39:191-220, 1999). In a R6/1 transgenic mouse model of HD expressing a human mutated htt exon1, a
116 CAG repeat, mice at 11, 19 and 35 weeks show a progressive increase in lipid peroxidation
with normal levels of superoxide dismutase (SOD) at 11 weeks similar to wild type
(WT) mice; a maximum level at 19 weeks, above that observed in WT mice and corresponding
to the early phase of disease progression; and finally, decreasing levels at 35 weeks
below that observed in WT mice (
Pérez-Sevriano et al., Brain Res. 951:36-42, 2002). The increase in SOD activity is attributable to a compensatory neuroprotective
mechanism, with decreased levels at 35 weeks corresponding to a failed protective
mechanism. Concomitant with the levels of SOD, levels of calcium dependent NOS was
the same for 11 week mice in both WT and R6/1 mice, but increased significantly at
19 weeks and decreased at 35 weeks relative to WT control mice. Levels of nNOS expression
also increased dramatically relative to controls at 19 weeks but were decreased significantly
relative to controls at 35 weeks. No significant differences were observed in levels
of eNOS expression, nor could iNOS protein be detected during progression of the disease.
The progressive phenotypic expression of the disease, as measured by increased weight
loss, feet clasping behavior, and horizontal and vertical movements, are consistent
with changes in NOS activity and nNOS expression. Finally, the effects ofL-NAME administration
to both R6/2 transgenic HD mice and WT mice showed improved levels of clasping behavior
at a 10 mg/kg dose similar to controls, which worsened at the highest dose of 500
mg/kg (
Deckel et al., Brain Res. 919 (1):70-81, 2001). An improvement in weight increase in HD mice was also significant at the 10 mg/kg
dose, but decreased relative to controls at high dose levels of L-NAME. These results
demonstrate that administration of an appropriate dose of an NOS inhibitor, such as,
for example, a compound of the invention, can be beneficial in the treatment of HD.
(e) Multiple Sclerosis (MS)
(f) Methamphetamine-Induced Neurotoxicity
[0155] Administration of a compound of the invention, either alone or in combination with
another therapeutic agent, such as, for example, an NMDA antagonist, may be useful
for the protection or treatment of any of the neurodegenerative diseases described
herein. Further, the compounds of the invention may be tested in standard assays used
to assess neuroprotection (see for example,
Am. J. Physiol. 268:R286, 1995).
Chemical Dependencies and Drug Addictions (e.g., dependencies on drugs, alcohol and
nicotine)
[0156] A key step in the process of drug-induced reward and dependence is the regulation
of dopamine release from mesolimbic dopaminergic neurons. Chronic application of cocaine
alters the expression of the key protein controlling the synaptic level of dopamine
- the dopamine transporter (DAT).
(a) Cocaine Addiction
[0157] Studies have shown that animals reliably self-administer stimulants intravenously
and that dopamine is critical in their reinforcing effects. Recently NO containing
neurons have been shown to co-localize with dopamine in areas of the striatum and
ventral tegmental area and that NO can modulate stimulant-evoked dopamine (DA) release.
Administration of dopamine D1 receptor antagonists decrease the levels of straital
NADPH-diaphorase staining, a marker for NOS activity, while D2 antagonists produce
the opposite effect. L-Arginine, the substrate of NOS, is also a potent modulator
of DA release. Also, multiple NO-generating agents increase DA efflux or inhibit reuptake
both
in vitro and
in vivo. L-NAME has been shown to significantly alter cocaine reinforcement by decreasing
the amount of self-administration and by increasing the inter-response time between
successive cocaine injections (
Pudiak and Bozarth, Soc. Neurosci. Abs. 22:703, 1996). This indicates that NOS inhibition may be useful in the treatment of cocaine addiction.
(b) Morphine/Opioid induced tolerance and withdrawal symptoms
[0158] There is much evidence supporting the role of both the NMDA and NO pathways in opioid
dependence in adult and infant animals. Adult or neonatal rodents injected with morphine
sulfate develop behavioral withdrawal after precipitation with naltrexone. The withdrawal
symptoms after naltrexone initiation can be reduced by administration of NOS inhibitors,
such as 7-NI or L-NAME (
Zhu and Barr, Psychopharmacology 150(3):325-336, 2000). In a related study, it was shown that the more nNOS selective inhibitor 7-NI attenuated
more of the morphine induced withdrawal symptoms including mastication, salivation
and genital effects than the less selective compounds (
Vaupel et al., Psychopharmacology (Berl.) 118(4):361-8, 1995).
(c) Ethanol Tolerance and Dependence
[0159] Among the factors that influence alcohol dependence, tolerance to the effects of
ethanol is an important component because it favors the exaggerated drinking of alcoholic
beverages (
Lê and Kiianmaa, Psychopharmacology (Berl.) 94:479-483, 1988). In a study with rats, ethanol tolerance to motor incoordination and hypothermia
develop rapidly and can be blocked by i.c.v administration of 7-NI without altering
cerebral ethanol concentrations (
Wazlawik and Morato, Brain Res. Bull. 57(2):165-70, 2002). In other studies, NOS inhibition with L-NAME (
Rezvani et al.., Pharmacol. Biochem Behav. 50:265-270, 1995) or by i.c.v. injection of nNOS antisense (
Naassila et al., Pharmacol. Biochem. Behav. 67:629-36, 2000) reduced ethanol consumption in these animals.
[0160] Administration of a compound of the invention, either alone or in combination with
another therapeutic agent, such as, for example, an NMDA antagonist, may be useful
for the treatment of chemical dependencies and drug addictions.
Epilepsy
[0161] Co-administration of 7-NI with certain anticonvulsants, such as carbamazepine, shows
a synergistic protective effect against amygdala-kindled seizures in rats at concentrations
that do not alter roto-rod performance (
Borowicz et al., Epilepsia 41(9:112-8, 2000). Thus, an NOS inhibitor, such as, for example, a compound of the invention, either
alone or in combination with another therapeutic agent, such as, for example, an antiepileptic
agent, may be useful for the treatment of epilepsy or a similar disorder. Examples
of antiepileptic agents useful in a combination of the invention include carbamazepine,
gabapentin, lamotrigine, oxcarbazepine, phenyloin, topiramate, and valproate.
Diabetic Nephropathy
[0162] Urinary excretion of NO byproducts is increased in diabetic rats after streptozotocin
treatment and increased NO synthesis has been suggested to be involved in diabetic
glomerular hyperfiltration. The neuronal isoform nNOS is expressed in the loop of
Henle and mucula densa of the kidney and inhibition of this isoform using 7-NI reduces
glomerular filtration without affecting renal arteriole pressure or renal blood flow
(
Sigmon et al., Gen. Pharmacol. 34(2):95-100, 2000). Both the non-selective NOS inhibitor L-NAME and the nNOS selective 7-NI normalize
renal hyperfiltration in diabetic animals (
Ito et al., J. Lab Clin. Med. 138(3):177-185,2001). Therefore, administration of a compound of the invention may be useful for the
treatment of diabetic nephropathy.
Combination Formulations, and Uses Thereof
[0163] In addition to the formulations described above, one or more compounds of the invention
can be used in combination with other therapeutic agents. For example, one or more
compounds of the invention can be combined with another NOS inhibitor. Exemplary inhibitors
useful for this purpose include, without limitation, those described in
U.S. Patent No. 6,235,747;
U.S. Patent Applications Serial Nos. 09/127,158,
09/325,480,
09/403,177,
09/802,086,
09/826,132,
09/740,385,
09/381,887,
10/476,958,
10/483,140,
10/484,960,
10/678,369,
10/819,853,
10/938,891; International Publication Nos.
WO 97/36871,
WO 98/24766,
WO 98/34919,
WO 99/10339,
WO 99/11620, and
WO 99/62883.
[0164] In another example, one or more compounds of the invention can be combined with an
antiarrhythmic agent. Exemplary antiarrhythmic agents include, without limitation,
lidocaine and mixiletine.
[0165] GABA-B agonists, alpha-2-adrenergic receptor agonists, cholecystokinin antagonists,
5HT
1B/1D agonists, or CGRP antagonists can also be used in combination with one or more compounds
of the invention. Non-limiting examples of alpha-2-adrenergic receptor agonists include
clonidine, lofexidine, and propanolol. Non-limiting examples of cholecystokinin antagonists
include L-365,260; CI-988; LY262691; S0509, or those described in
U.S. Patent No. 5,618,811. Non-limiting examples of 5HT
1B/1D agonists that may be used in combination with a compound of the invention include
dihydroegotamine, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan,
or zolmitriptan. Non-limiting examples of CGRP antagonists that may be used in combination
with a compound of the invention include quinine analogues as described in International
Publication No.
WO9709046, non-peptide antagonists as described in International Publication Nos.
WO0132648,
WO0132649,
WO9811128,
WO9809630,
WO9856779,
WO0018764, or other antagonists such as SB-(+)-273779 or BIBN-4096BS.
[0166] Substance P antagonists, also known as NK
1 receptor antagonists, are also useful in combination with one or more compounds of
the invention. Exemplary inhibitors useful for this purpose include, without limitation,
those compounds disclosed in
U.S. Patent Nos. 3,862,114,
3,912,711,
4,472,305,
4,481,139,
4,680,283,
4,839,465,
5,102,667,
5,162,339,
5,164,372,
5,166,136,
5,232,929,
5,242,944,
5,300,648,
5,310,743,
5,338,845,
5,340,822,
5,378,803,
5,410,019,
5,411,971,
5,420,297,
5,422,354,
5,446,052,
5,451,586,
5,525,712,
5,527,811,
5,536,737,
5,541,195,
5,594,022,
5,561,113,
5,576,317,
5,604,247,
5,624,950, and
5,635,510; International Publication Nos.
WO 90/05525,
WO 91/09844,
WO 91/12266,
WO 92/06079,
WO 92/12151,
WO 92/15585,
WO 92/20661,
WO 92/20676,
WO 92/21677,
WO 92/22569,
WO 93/00330,
WO 93/00331,
WO 93/01159,
WO 93/01160,
WO 93/01165,
WO 93/01169,
WO 93/01170,
WO 93/06099,
WO 93/10073,
WO 93/14084,
WO 93/19064,
WO 93/21155,
WO 94/04496,
WO 94/08997,
WO 94/29309,
WO 95/11895,
WO 95/14017,
WO 97/19942,
WO 97/24356,
WO 97/38692,
WO 98/02158, and
WO 98/07694; European Patent Publication Nos.
284942,
327009,
333174,
336230,
360390,
394989,
428434,
429366,
443132,
446706,
484719,
499313,
512901,
512902,
514273,
514275,
515240,
520555,
522808,
528495,
532456, and
591040.
[0167] Suitable classes of antidepressant agents that may be used in combination with a
compound of the invention include, without limitation, norepinephrine re-uptake inhibitors,
selective serotonin re-uptake inhibitors (SSRIs), selective noradrenaline/norepinephrine
reuptake inhibitors (NARIs), monoamine oxidase inhibitors (MAOs), reversible inhibitors
of monoamine oxidase (RIMAs), dual serotonin/noradrenaline re-uptake inhibitors (SNRIs),
α-adrenoreceptor antagonists, noradrenergic and specific serotonergic antidepressants
(NaSSAs), and atypical antidepressants.
[0168] Non-limiting examples of norepinephrine re-uptake inhibitors include tertiary amine
tricyclics and secondary amine tricyclics, such as, for example, adinazolam, amineptine,
amitriptyline, amoxapine, butriptyline, clomipramine, demexiptiline, desmethylamitriptyline,
desipramine, dibenzepin, dimetacrine, doxepin, dothiepin, femoxetine, fluacizine,
imipramine, imipramine oxide, iprindole, lofepramine, maprotiline, melitracen, metapramine,
norclolipramine, nortriptyline, noxiptilin, opipramol, perlapine, pizotifen, pizotyline,
propizepine, protriptyline, quinupramine, tianeptine, trimipramine, trimipramineamiltriptylinoxide,
and pharmaceutically acceptable salts thereof.
[0169] Non-limiting examples of selective serotonin re-uptake inhibitors include, for example,
fluoxetine, fluvoxamine, paroxetine, and sertraline, and pharmaceutically acceptable
salts thereof.
[0170] Non-limiting examples of selective noradrenaline/norepinephrine reuptake inhibitors
include, for example, atomoxetine, bupropion; reboxetine, and tomoxetine.
[0171] Non-limiting examples of selective monoamine oxidase inhibitors include, for example,
isocarboxazid, phenezine, tranylcypromine and selegiline, and pharmaceutically acceptable
salts thereof. Other monoamine oxidase inhibitors useful in a combination of the invention
include clorgyline, cimoxatone, befloxatone, brofaromine, bazinaprine, BW-616U (Burroughs
Wellcome), BW-1370U87 (Burroughs Wellcome), CS-722 (RS-722) (Sankyo), E-2011 (Eisai),
harmine, harmaline, moclobemide, PharmaProjects 3975 (Hoechst), RO 41-1049 (Roche),
RS-8359 (Sankyo), T-794 (Tanabe Seiyaku), toloxatone, K-Y 1349 (Kalir and Youdim),
LY-51641 (Lilly), LY-121768 (Lilly), M&B 9303 (May & Baker), MDL 72394 (Marion Merrell),
MDL 72392 (Marion Merrell), sercloremine, and MO 1671, and pharmaceutically acceptable
salts thereof. Suitable reversible inhibitors of monoamine oxidase that may be used
in the present invention include, for example, moclobemide, and pharmaceutically acceptable
salts thereof.
[0172] Non-limiting examples of dual serotonin/norepinephrine reuptake blockers include,
for example, duloxetine, milnacipran, mirtazapine, nefazodone, and venlafaxine.
[0173] Non-limiting examples of other antidepressants that may be used in a method of the
present invention include adinazolam, alaproclate, amineptine, amitriptyline/chlordiazepoxide
combination, atipamezole, azamianserin, bazinaprine, befuraline, bifemelane, binodaline,
bipenamol, brofaromine, caroxazone, cericlamine, cianopramine, cimoxatone, citalopram,
clemeprol, clovoxamine, dazepinil, deanol, demexiptiline, dibenzepin, dothiepin, droxidopa,
enefexine, estazolam, etoperidone, fengabine, fezolamine, fluotracen, idazoxan, indalpine,
indeloxazine, levoprotiline, litoxetine; medifoxamine, metralindole, mianserin, minaprine,
montirelin, nebracetam, nefopam, nialamide, nomifensine, norfluoxetine, orotirelin,
oxaflozane, pinazepam, pirlindone, ritanserin, rolipram, sercloremine, setiptiline,
sibutramine, sulbutiamine, sulpiride, teniloxazine, thozalinone, thymoliberin, tiflucarbine,
tofenacin, tofisopam, toloxatone, veralipride, viqualine, zimelidine, and zometrapine,
and pharmaceutically acceptable salts thereof, and St. John's wort herb, or Hypencuin
perforatum, or extracts thereof.
[0174] In another example, opioids can be used in combination with one or more compounds
of the invention. Exemplary opioids useful for this purpose include, without limitation,
alfentanil, butorphanol, buprenorphine, dextromoramide, dezocine, dextropropoxyphene,
codeine, dihydrocodeine, diphenoxylate, etorphine, fentanyl, hydrocodone, hydromorphone,
ketobemidone, loperamide, levorphanol, levomethadone, meperidine, meptazinol, methadone,
morphine, morphine-6-glucuronide, nalbuphine, naloxone, oxycodone, oxymorphone, pentazocine,
pethidine, piritramide, propoxylphene, remifentanil, sulfentanyl, tilidine, and tramadol.
[0175] In yet another example, anti-inflammatory compounds, such as steroidal agents or
non-steroidal anti-inflammatory drugs (NSAIDs), can be used in combination with one
or more compounds of the invention. Non-limiting examples of steroidal agents include
prednisolone and cortisone. Non-limiting examples of NSAIDs include acemetacin, aspirin,
celecoxib, deracoxib, diclofenac, diflunisal, ethenzamide, etofenamate, etoricoxib,
fenoprofen, flufenamic acid, flurbiprofen, lonazolac, lornoxicam, ibuprofen, indomethacin,
isoxicam, kebuzone, ketoprofen, ketorolac, naproxen, nabumetone, niflumic acid, sulindac,
tolmetin, piroxicam, meclofenamic acid, mefenamic acid, meloxicam, metamizol, mofebutazone,
oxyphenbutazone, parecoxib, phenidine, phenylbutazone, piroxicam, propacetamol, propyphenazone,
rofecoxib, salicylamide, suprofen, tiaprofenic acid, tenoxicam, valdecoxib, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide,
N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide, 2-(3,4-difluorophenyl)-4-(3-hydroxy-3-methylbutoxy)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone,
and 2-(3,5-difluorophenyl)-3-[4-(methylsulfonyl)phenyl]-2-cyclopenten-1-one). Compounds
of the invention may also be use in combination with acetaminophen.
[0176] Any of the above combinations can be used to treat any appropriate disease, disorder,
or condition. Exemplary uses for combinations of a compound of the invention and another
therapeutic agent are described below.
Opioid-NOS Inhibitor Combinations in Chronic, Neuropathic Pain
[0177] Nerve injury can lead to abnormal pain states known as neuropathic pain. Some of
the clinical symptoms include tactile allodynia (nociceptive responses to normally
innocuous mechanical stimuli), hyperalgesia (augmented pain intensity in response
to normally painful stimuli), and spontaneous pain. Spinal nerve ligation (SNL) in
rats is an animal model of neuropathic pain that produces spontaneous pain, allodynia,
and hyperalgesia, analogous to the clinical symptoms observed in human patients (
Kim and Chung, Pain 50:355-363, 1992;
Seltzer, Neurosciences 7:211-219, 1995).
[0178] Neuropathic pain can be particularly insensitive to opioid treatment (
Benedetti et al., Pain 74:205-211, 1998) and is still considered to be relatively refractory to opioid analgesics (
MacFarlane et al., Pharmacol. Ther. 75:1-19, 1997;
Watson, Clin. J. Pain 16:S49-S55, 2000). While dose escalation can overcome reduced opioid effectiveness, it is limited
by increased side effects and tolerance. Morphine administration is known to activate
the NOS system, which limits the analgesic action of this drug (
Machelska et al., NeuroReport 8:2743-2747, 1997;
Wong et al., Br. J. Anaesth. 85:587, 2000;
Xiangqi and Clark, Mol. Brain. Res. 95:96-102, 2001). However, it has been shown that the combined systemic administration of morphine
and L-NAME can attenuate mechanical and cold allodynia at subthreshold doses at which
neither drug administered alone was effective (
Ulugol et al., Neurosci. Res. Com. 30(3):143-153, 2002). The effect of L-NAME co-administration on morphine analgesia appears to be mediated
by nNOS, as L-NAME loses its ability to potentiate morphine analgesia in nNOS null-mutant
mice (
Clark and Xiangqi, Mol. Brain. Res. 95:96-102,2001). Enhanced analgesia has been demonstrated in the tail-flick or paw pressure models
using coadministration of L-NAME or 7-NI with either a mu-, delta-, or kappa-selective
opioid agonist (
Machelska et al., J. Pharmacol. Exp. Ther. 282:977-984, 1997).
[0179] While opioids are an important therapy for the treatment of moderate to severe pain,
in addition to the usual side effects that limit their utility, the somewhat paradoxical
appearance of opioid-induced hyperalgesia may actually render paitents more sensitive
to pain and potentially aggravate their pain (
Angst and Clark, Anesthesiology, 2006, 104(3), 570-587;
Chu et. al. J. Pain 2006, 7(1) 43-48). The development of tolerance and opioid induced hyperalgesia is consistent with
increased levels of NO production in the brain. The reduced analgesic response to
opioids is due to an NO-induced upregulated hyperalgesic response (
Heinzen and Pollack, Brain Res. 2004, 1023, 175-184).
[0180] Thus, the combination of an nNOS inhibitor with an opioid (for example, those combinations
described above) can enhance opioid analgesia in neuropathic pain and prevent the
development of opioid tolerance and opioid-induced hyperalgesia.
Antidepressant-NOS Inhibitor Combinations for Chronic Pain, Neuropathic Pain, Chronic
Headache or Migraine
[0181] Many antidepressants are used for the treatment of neuropathic pain (
McQuay et al., Pain 68:217-227, 1996) and migraine (
Tomkins et al., Am. J. Med. 111:54-63, 2001), and act via the serotonergic or noradrenergic system. NO serves as a neuromodulator
of these systems (
Garthwaite and Boulton, Annu. Rev. Physiol. 57:683, 1995). 7-NI has been shown to potentiate the release of noradrenaline (NA) by the nicotinic
acetylcholine receptor agonist DMPP via the NA transporter (
Kiss et al., Neuroscience Lett. 215:115-118, 1996). It has been shown that local administration of antidepressants, such as paroxetine,
tianeptine, and imipramine decrease levels of hippocampal NO (
Wegener et al., Brain Res. 959:128-134, 2003). It is likely that NO is important in the mechanism by which antidepressants are
effective for treating pain and depression, and that a combination of an nNOS inhibitor
with an antidepressant, such as, for example, those combinations described above,
will produce better treatments.
Serotonin 5Hf1B/1D/1F Agonist or CGRP Antagonist and NOS Inhibitor Combinations in Migraine
[0182] Administration of Glyceryl trinitrate (GTN), an NO donor, induces immediate headaches
in normal individuals and results in delayed migraine attacks in migraineurs with
a 4-6 hour latency period (
Iversen et al., Pain 38:17-24, 1989). In patients with migraine attack, levels of CGRP (Calcitonin Gene Related Peptide),
a potent vasodialator, in the carotid artery correlate with the onset and ablation
of migraine attack (
Durham, Curr Opin Investig Drugs 5(7):731-5, 2004). Sumatriptan, an antimigraine drug having affinity at 5HT
1B, 5HT
1D, and 5HT
1F receptors, reduces GTN-induced immediate headache and in parallel contracts cerebral
and extracerebral arteries (
Iversen and Olesen, Cephalagia 13(Suppl 13):186, 1993). The antimigraine drug rizatriptan also reduces plasma levels of CGRP following
migraine pain reduction (
Stepien et al., Neurol. Neurochir. Pol. 37(5):1013-23, 2003). Both NO and CGRP have therefore been implicated as a cause for migraine. Serotonin
5HT
1B/1D agonists have been shown to block NMDA receptor-evoked NO signaling in brain cortex
slices (
Strosznajder et al., Cephalalgia 19(10):859, 1999). These results suggest that a combination of a compound of the invention and a selective
or non-selective 5HT
1B/1D/1F agonist or a CGRP antagonist, such as those combinations described above, would be
useful for the treatment of migraine.
Pharmaceutical Compositions
[0183] The compounds of the invention are preferably formulated into pharmaceutical compositions
for administration to human subjects in a biologically compatible form suitable for
administration
in vivo. Accordingly, in another aspect, the present invention provides a pharmaceutical composition
comprising a compound of the invention in admixture with a suitable diluent or carrier.
[0184] The compounds of the invention may be used in the form of the free base, in the form
of salts, solvates, and as prodrugs. All forms are within the scope of the invention.
In accordance with the methods of the invention, the described compounds or salts,
solvates, or prodrugs thereof may be administered to a patient in a variety of forms
depending on the selected route of administration, as will be understood by those
skilled in the art. The compounds of the invention may be administered, for example,
by oral, parenteral, buccal, sublingual, nasal, rectal, patch, pump, or transdermal
administration and the pharmaceutical compositions formulated accordingly. Parenteral
administration includes intravenous, intraperitoneal, subcutaneous, intramuscular,
transepithelial, nasal, intrapulmonary, intrathecal, rectal, and topical modes of
administration. Parenteral administration may be by continuous infusion over a selected
period of time.
[0185] A compound of the invention may be orally administered, for example, with an inert
diluent or with an assimilable edible carrier, or it may be enclosed in hard or soft
shell gelatin capsules, or it may be compressed into tablets, or it may be incorporated
directly with the food of the diet. For oral therapeutic administration, a compound
of the invention may be incorporated with an excipient and used in the form of ingestible
tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers,
and the like.
[0186] A compound of the invention may also be administered parenterally. Solutions of a
compound of the invention can be prepared in water suitably mixed with a surfactant,
such as hydroxypropylcellulose. Dispersions can also be prepared in glycerol, liquid
polyethylene glycols, DMSO and mixtures thereof with or without alcohol, and in oils.
Under ordinary conditions of storage and use, these preparations may contain a preservative
to prevent the growth of microorganisms. Conventional procedures and ingredients for
the selection and preparation of suitable formulations are described, for example,
in
Remington's Pharmaceutical Sciences (2003 - 20th edition) and in
The United States Pharmacopeia: The National Formulary (USP 24 NF 19), published in
1999.
[0187] The pharmaceutical forms suitable for injectable use include sterile aqueous solutions
or dispersions and sterile powders for the extemporaneous preparation of sterile injectable
solutions or dispersions. In all cases the form must be sterile and must be fluid
to the extent that may be easily administered via syringe.
[0188] Compositions for nasal administration may conveniently be formulated as aerosols,
drops, gels, and powders. Aerosol formulations typically include a solution or fine
suspension of the active substance in a physiologically acceptable aqueous or non-aqueous
solvent and are usually presented in single or multidose quantities in sterile form
in a sealed container, which can take the form of a cartridge or refill for use with
an atomizing device. Alternatively, the sealed container may be a unitary dispensing
device, such as a single dose nasal inhaler or an aerosol dispenser fitted with a
metering valve which is intended for disposal after use. Where the dosage form comprises
an aerosol dispenser, it will contain a propellant, which can be a compressed gas,
such as compressed air or an organic propellant, such as fluorochlorohydrocarbon.
The aerosol dosage forms can also take the form of a pump-atomizer.
[0189] Compositions suitable for buccal or sublingual administration include tablets, lozenges,
and pastilles, where the active ingredient is formulated with a carrier, such as sugar,
acacia, tragacanth, or gelatin and glycerine. Compositions for rectal administration
are conveniently in the form of suppositories containing a conventional suppository
base, such as cocoa butter.
[0190] The compounds of the invention may be administered to an animal alone or in combination
with pharmaceutically acceptable carriers, as noted above, the proportion of which
is determined by the solubility and chemical nature of the compound, chosen route
of administration, and standard pharmaceutical practice.
[0191] The dosage of the compounds of the invention, and/or compositions comprising a compound
of the invention, can vary depending on many factors, such as the pharmacodynamic
properties of the compound; the mode of administration; the age, health, and weight
of the recipient; the nature and extent of the symptoms; the frequency of the treatment,
and the type of concurrent treatment, if any; and the clearance rate of the compound
in the animal to be treated. One of skill in the art can determine the appropriate
dosage based on the above factors. The compounds of the invention may be administered
initially in a suitable dosage that may be adjusted as required, depending on the
clinical response. In general, satisfactory results may be obtained when the compounds
of the invention are administered to a human at a daily dosage of between 0.05 mg
and 3000 mg (measured as the solid form). A preferred dose ranges between 0.05-500
mg/kg, more preferably between 0.5-50 mg/kg.
[0192] A compound of the invention can be used alone or in combination with other agents
that have NOS activity, or in combination with other types of treatment (which may
or may not inhibit NOS) to treat, prevent, and/or reduce the risk of stroke, neuropathic
or migraine pain, or other disorders that benefit from NOS inhibition. In combination
treatments, the dosages of one or more of the therapeutic compounds may be reduced
from standard dosages when administered alone. In this case, dosages of the compounds
when combined should provide a therapeutic effect.
[0193] In addition to the above-mentioned therapeutic uses, a compound of the invention
can also be used in diagnostic assays, screening assays, and as a research tool.
[0194] In diagnostic assays, a compound of the invention may be useful in identifying or
detecting NOS activity. For such a use, the compound may be radiolabelled (as described
elsewhere herein) and contacted with a population of cells of an organism. The presence
of the radiolabel on the cells may indicate NOS activity.
[0195] In screening assays, a compound of the invention may be used to identify other compounds
that inhibit NOS, for example, as first generation drugs. As research tools, the compounds
of the invention may be used in enzyme assays and assays to study the localization
of NOS activity. Such information may be useful, for example, for diagnosing or monitoring
disease states or progression. In such assays, a compound of the invention may also
be radiolabeled.
[0196] The following non-limiting examples are illustrative of the present invention:
Example 1: The Preparation of Compound 4
[0197]
- (a) Preparation of compound 2: 1H-Indol-5-ylamine (compound 1, 100 mg, 0.757 mmol) was dissolved in anhydrous tetrahydrofuran (4.5 mL) in a small
argon purged flask. Benzoyl isothiocyanate (123 mg, 0.757 mmol) was added dropwise
and the reaction was stirred at room temperature under argon for 60 hours. 3-(Diethylenetriamino)propyl-functionalized
silica gel (0.5 g) was added, the mixture stirred for an additional 30 minutes, and
the mixture filtered using 3:7 ethyl acetate/hexanes as the eluant. The product (compound
2, 90 mg, 40.3% yield) was obtained via purification by silica gel column chromatography
(30% ethyl acetate/hexanes); 1H NMR (CDCl3) δ: 6.59 (s, 1H), 7.25-7.26 (m, 2H), 7.51 (s, 1H), 7.54-7.66 (m, 3H), 7.93 (m, 3H),
8.32 (br s, 1H), 9.15 (s, 1H), 12.50 (s, 1H).
- (b) Preparation of compound 3: 1-Benzoyl-3-(1H-indol-5-yl)-thiourea, (compound 2, 90 mg, 0.305 mmol) was dissolved in anhydrous tetrahydrofuran (5 mL) in a small
argon purged flask. The reaction vessel was fitted with a condenser and placed in
an oil bath preheated to 60 °C. Aqueous 2M sodium hydroxide solution (0.6 mL) was
added and the reaction was stirred under reflux for 4 hours. Workup gave compound
3 (22 mg, 38.0% yield).
- (c) Preparation of compound 4: (1H-Indol-5-yl)-thiourea (compound 3, 22 mg, 0.116 mmol) was dissolved in DMF (2.5 mL). The solution was stirred under
argon as ethyl iodide (18.1 mg, 0.116 mmol) was added dropwise. Potassium carbonate
(48.01 mg, 0.347 mmol) was added and the reaction was stirred for 20 hours at room
temperature. The reaction was treated with water (5 mL) and dichloromethane (20 mL)
and transferred to a separatory funnel. The organic layer was dried (MgSO4) filtered, and concentrated to give compound 4.
Example 2: The Preparation of Compound 5
[0198]
- (a) Preparation of compound 5: 1H-Indol-5-ylamine (compound 1, 59 mg, 0.45 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(142.7 mg, 0.47 mmol) were dissolved in absolute ethanol (2.0 mL) in a dry, argon
purged flask. The reaction was stirred under argon at ambient temperature for 17 hours.
The solution was diluted with diethyl ether (20 mL), resulting in the formation of
a tan precipitate, which was collected and washed with ether and dried under suction
to provide compound 5 as a tan solid (121.4 mg, HBr salt, 84% yield); 1H NMR (DMSO-d6) δ: 10.9 (s, 1 H, NH), 7.74 (d, 1H, J=3.4), 7.63 (d, 1H, J=4.88), 7.35
(d, 1H, J=8.3), 7.29 (s, 1H), 7.12 (t, 1H, J=4.88), 7.03 (s, 1H), 6.69 (d, 1H, J=8.3),
6.35 (br s, 2H), 6.35 (s, 1H).
Example 3: The Preparation of Compound 9
[0199]
- (a) Preparation of compound 7: 6-Nitroindole (compound 6, 95 mg, 0.59 mmol) and 1-(2-chloroethyl)pyrrolidine hydrocloride (100 mg, 0.59 mmol)
were dissolved in DMF (3ml) in an argon purged flask. The reaction was placed in an
oil bath preheated to 50 °C and stirred under argon in the presence of potassium carbonate
(244 mg, 1.77 mmol) for 24 hours. After cooling, the reaction vessel was placed in
an ice bath and the reaction was diluted with ice water (10 mL) and ethyl acetate.
The reaction was transferred to a separatory funnel and the organic layer collected.
The organic layer was washed twice with brine, and the combined aqueous washes were
re-extracted with ethyl acetate. The combined organic extracts were dried over sodium
sulfate, filtered, and concentrated to afford a yellow oil. The product was taken
up in methanol (2 mL) and acidified with 2N HCl (15 mL), followed by filtration to
remove any insoluble material. The reaction was evaporated to dryness and the residual
oil was placed under high vacuum overnight to give a yellow solid (compound 7, 63 mg, 41.2% yield); 1H NMR (CDCl3; free base) δ: 8.37 (s, 1H), 8.02 (dd, 1H, J=2.0, 8.5), 7.64 (d, 1H, J=8.5), 7.46
(d, 1H, J=3.2), 6.59 (d, 1H, J=3.2), 4.34 (t, 2H, J=6.9), 2.92 (t, 2H, J=6.9), 2.56
(m, 4H), 1.82-1.74 (m, 4H); MS (APCI+) 260.0 (M+1).
- (b) Preparation of compound 8: 6-Nitro-1-(2-pyrrolidin-1-yl-ethyl)-1H indole (compound 7, 63 mg, 0.243 mmol) was placed in a small, argon purged flask fitted with a condenser
and magnetic stirbar. Denatured absolute ethanol (5 mL) was added, followed by tin
(II) chloride hydrate (202 mg, 1.07 mmol). The solution was heated to reflux in an
oil bath for 1 hour. After cooling, the mixture was diluted with ethyl acetate (10
mL) and aqueous 3M sodium hydroxide solution (5 mL). The reaction was transferred
to a separatory funnel and the organic layer was washed twice more with aqueous 3M
sodium hydroxide solution, followed by washing with brine. The combined organic extracts
were dried over sodium sulfate, filtered, and concentrated to afford a brown oil.
The product was purified via silica gel column chromatography (5% 2M NH3 in methanol/95% dichloromethane) to afford compound 8 as a brown oil (51.6 mg, 92.6% yield); 1H NMR (CDCl3) δ: 7.34 (d, III, J=8.5), 6.93 (d, 1H, J=3.2), 6.66 (s, 1H), 6.56 (dd, 1H, J=8.5,
2.0), 4.17 (t, 2H, J=7.3), 2.90 (t, 2H, J=7.3), 2.57 (m, 4H), 1.83-1.76 (m, 4H); MS
(ESI+): 230 (M+1).
- (c) Preparation of compound 9: 1-(2-Pyrrolidin-1-yl-ethyl)-1H-indol-6-ylamine (compound 8, 51.6 mg, 0.225 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(68 mg, 0.225 mmol) were dissolved in methanol (4 mL) in a small, argon purged flask.
The reaction was stirred under argon for 21 hours at ambient temperature. The solvent
was evaporated and the product was purified via silica gel column chromatography (5%
2M NH3 in Methanol/95% dichloromethane) to afford compound 9 as a brown oil (86 mg, > 100% yield, note: the product is hydroscopic); 1H NMR (CDCl3; 200 MHz) δ: 7.57 (d, 1H, J=8.5), 7.43 - 7.40 (m, 2H), 7.09-7.05 (m, 2H), 6.99 (s,
1H), 6.78 (dd, 1H, J=1.6, 8.1), 6.44 (d, 1H, J=3.2), 4.88 (br s, 2 H, NH2), 4.22 (t,
2H, J = 7.7), 2.87 (t, 2H, J = 7.7), 2.55 (br s, 4H), 1.78 (m, 4H).
Example 4: Preparation of Compound 12
[0200]
- (a) Preparation of compound 10: 6-Nitroindole (compound 6, 315.3 mg, 1.94 mmol), potassium carbonate (804 mg, 5.82 mmol), and 2-dimethylaminoethyl
chloride hydrochloride (363 mg, 2.52 mmol) were dissolved in DMF (4 mL) in an argon-purged
flask. The reaction was placed in an oil bath preheated to 50 °C and stirred under
argon for 21.5 hours. The mixture was transferred to a flask and an additional aliquot
of 2-dimethylaminoethyl chloride hydrochloride was added (363 mg, 2.52 mmol). The
flask was sealed and the mixture heated for an additional 24 hours. After cooling
to room temperature the reaction was transferred to a separatory funnel and diluted
with ethyl acetate (25 mL) and ice water (30 mL). The layers were separated and the
organic layer was washed twice more with ice water (2 x 20 mL). The organic extracts
were dried over sodium sulfate, filtered, and concentrated to afford a solid. The
product was purified via silica gel column chromatography (1:1 ethyl acetate/hexanes
to elute the starting material followed by 5% 2M NH3 in methanol/95% dichloromethane) to afford compound 10 as a yellow oil (96.5 mg, 23% yield); 1H NMR (CDCl3) δ: 8.35 (s, 1H), 7.99 (dd, 1H, J=1.6, 8.9), 7.64 (d, J=8.9), 7.46 (d, 1H, J=2.8),
6.59 (d, 1H, J=2.8); MS (APCI+) 234 (M+1).
- (b) Preparation of compound 11: Dimethyl-[2-(6-nitro-indol-1-yl)-ethyl]-amine (compound 10, 74.3 mg, 0.339 mmol) and tin (II) chloride hydrate (267 mg, 1.41 mmol) were placed
in a small, argon purged flask fitted with a condenser and magnetic stirbar. Denatured
ethanol (5 mL) was added. The solution was heated to reflux in an oil bath for 3 hours.
The mixture was diluted with ethyl acetate (20 mL) and aqueous 3M sodium hydroxide
solution. The reaction was transferred to a separatory funnel and the organic layer
collected. The organic layer was washed twice more with aqueous 3M sodium hydroxide
solution (2 x 20 mL). The organic layer was dried over sodium sulfate, filtered, and
concentrated. The product was purified via silica gel column chromatography to afford
compound 11 as a black oil (33.5 mg, 48.6% yield); 1H NMR (CDCl3) δ: 7.39 (d, 1H, J=8.5), 6.93 (d, 1H, J=3.2), 6.64 (s, 1H), 6.57 (d, 1H, J=8.5),
6.37 (d, 1H, J=3.2), 4.13 (t, 2H, J=7.3), 2.72 (t, 2H, J=7.3), 2.31 (s, 6H).
- (c) Preparation of compound 12: 1-(2-Dimethylamino-ethyl)-1H-indol-6-ylamine (compound 11, 33 mg, 0.162 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(53 mg, 0.178 mmol) were dissolved in methanol in a small, argon purged flask. The
reaction was stirred under argon for 27 hours at ambient temperature. The solvent
was evaporated and the residue was purified via silica gel column chromatography (5%
2M NH3 in methanol/ 95% dichloromethane) to afford a brown solid, which was recrystallized
from ethyl acetate and hexanes to provide compound 12, 17.8 mg, 35.2% yield; 1H NMR (DMSO-d6) δ: 7.74 (d, 1H, J=3.1), 7.60 (d, 1H, J=5.0), 7.45 (d, 1H, J=8), 7.24
(d, 1H, J=2.7), 7.11 (t, 1H, J=3.9), 6.91 (s, 1H), 6.59 (d, 1H, J=8), 6.34 (m, 3H),
4.19 (t, 2H, J=6.7), 2.59 (t, 2H, J=6.7), 2.20 (s, 6H).
Example 5: Preparation of Compound 15
[0201]
- (a) Preparation of compound 13: 1-(2-Dimethylamino-ethyl)-1H-indol-6-ylamine (compound 11, 311.4 mg, 1.532 mmol) was suspended in anhydrous tetrahydrofuran (5 mL) in an argon
purged flask. The addition of benzoyl isothiocyanate (0.25 mL, 1.84 mmol) caused the
amine to dissolve completely. The resulting brown solution was stirred at room temperature
under argon for 24 hours. The reaction was quenched with 3-(diethylenetriamino)propyl-functionalized
silica gel (482 mg), stirred for 2 hours, filtered, and concentrated. The product
was purified via silica gel column chromatography (3.5% 2M NH3 in methanol/95% dichloromethane) to provide compound 13 (180.1 mg, 32.1% yield); 1H NMR (CDCl3) δ: 2.31 (s, 6H), 2.70-2.77 (d, 2H), 4.20-4.27 (d, 2H), 6.49-6.50 (s, 1H), 7.19-7.26
(m, 1H), 7.54-7.63 (m, 5H), 7.89-7.93 (m, 2H), 8.14 (s, 1H).
- (b) Preparation of compound 14: 1-Benzoyl-3-[1-(2-dimethylamino-ethyl)-1H-indol-6-yl]-thiourea (compound 13, 133.6 mg, 0.365 mmol) was dissolved in anhydrous tetrahydrofuran (3 mL). Aqueous
2N sodium hydroxide solution (0.37 mL) was added, the flask purged with argon, and
the mixture was heated to reflux in an oil bath overnight. After cooling, the mixture
was diluted with distilled water (20 mL) and ethyl acetate (50 mL) and transferred
to a separatory funnel. The aqueous phase was removed and the organic phase collected.
The aqueous phase was re-extracted with ethyl acetate three times (3 x 20 mL). The
combined organic fractions were dried over sodium sulfate, filtered and concentrated
to provide compound 14 (45.2 mg, 47.2% yield).
- (c) Preparation of compound 15: [1-(2-Dimethylamino-ethyl)-1H-indol-6-yl]-thiourea (compound 14, 45.2 mg, 0.172 mmol) was dissolved in dry DMF (0.5 mL) and iodoethane (20 µL, 0.19
mmol) was added. The flask fitted with a plastic stopper, which was sealed with parafilm,
and the reaction mixture stirred at room temperature for 26 hours. The solution was
diluted with ethyl acetate (20 mL) resulting in a precipitate. Addition of 3N aqueous
sodium hydroxide solution (2 mL) was followed by transfer of the mixture to a separatory
funnel. The organic layer was collected and the aqueous layer was extracted with ethyl
acetate (20 mL). The organic fractions were combined, dried over sodium sulfate, filtered,
and condensed. The product was purified via silica gel column chromatography (5% 2M
NH3 in methanol/95% dichloromethane). The purified product was dissolved in methanol
(2 mL) and 1M HCl (2 ml) was added. Evaporation of the solvent afforded compound 15 as a yellow oil (6.1 mg, 10.9% yield of the dihydrochloride salt).
Example 6: Preparation of Compound 18
[0202]
- (a) Preparation of compound 17: [2-(5-Bromo-1H-indol-3-yl)-ethyl]-dimethylamine (compound 16, 372.4 mg, 1.394 mmol) (Slassi et al., U.S. Patent No. 5,998,438) was placed in an argon purged flame dried flask fitted with a condenser and stirbar.
Anhydrous tetrahydrofuran (10 mL) was added followed by tris(dibenzylideneacetone)dipalladium(0)
(63.8 mg, 0.05 eq) and tributylphosphine (0.42 mL, 0.139 mmol). The mixture was stirred
for 5 minutes at room temperature. Lithium bis(trimethylsilyl)amide (4.2 mL, 4.2 mmol)
was added and the resultant solution refluxed for 6 hours and then stirred at room
temperature for an additional 15 hours. The brown solution was quenched by adding
1M HCl (3 mL). The reaction was stirred for 15 minutes, followed by further addition
of 1M HCl (3 mL) to ensure an acidic solution. The mixture was transferred into a
separatory funnel and diluted with distilled water (20 mL). The aqueous phase was
extracted with ethyl acetate (2 x 20 mL). The aqueous phase was made basic by adding
aqueous 3M sodium hydroxide solution (3 mL) and extracted with ethyl acetate (3 x
20 mL). The combined organic extracts were dried over magnesium sulfate, filtered,
and concentrated to provide compound 17 as a brownish oil (209.6 mg, 74.1% yield); 1H NMR (CD3OD) δ: 2.52-2.55 (s, 6H), 2.86-2.89 (d, 2 H), 2.90-2.99 (d, 2H), 6.70-6.72 (d, 1H),
6.97 (s, 1H), 7.02 (s, 1H), 7.16-7.18 (d, 1H); MS: 204.0 (M+1).
- (b) Preparation of compound 18: 3-(2-Dimethylamino-ethyl)-1H-indol-5-ylamine (compound 17, 210 mg, 1.033 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(434 mg, 1.446 mmol) were dissolved in reagent grade ethanol (19 mL) in a small, argon
purged flask. The reaction was stirred under argon for 21 hours at ambient temperature
and placed in an ice-water bath to cool. Diethylether (50 mL) was added slowly while
stirring vigorously to produce a light yellow precipitate. The mixture was stirred
at 0 °C for 1 hour, followed by 4 hours of stirring at room temperature. The yellow
precipitate was collected through vacuum filtration and washed with ether. The sample
was dried under vacuum overnight at 110 °C to provide compound 18 as the hydrobromide salt (327.5 mg, 83% yield). To form the HCl salt, the hydrobromide
was dissolved in water (20 mL) and transferred to a separatory funnel, where it was
made basic through the addition of aqueous 2N sodium hydroxide solution (3 mL). The
mixture was extracted with dichloromethane (3 x 20 mL). The combined organic extracts
were dried over magnesium sulfate, filtered and concentrated. The residue was purified
via silica gel column chromatography (5 - 10% 2M NH3 in methanol/ 90-95% dichloromethane) to provide the free base as a brown oil. The
oil was dissolved in methanol (5 mL) and 1M aqueous HCl (3 mL) was added. The solvent
was removed and the oil dried under high vacuum to give compound 18 as the hydrochloride salt (87.5 mg, 30.2% yield); 1H NMR (free base, CDCl3) δ: 2.31 (s, 6H), 2.57-2.65 (t, 2H), 2.85-2.92 (t, 2H), 6.79-6.85 (dd, 1H), 6.94-6.95
(d, 1H), 7.03-7.08 (t, 1H), 7.18 (s, 1H), 7.19-7.22 (d, 1H), 7.39-7.41 (t, 2H), 8.61
1 (s, 1H); MS: 313.0 (M+1).
Example 7: Preparation of Compound 24
[0203]
- (a) Preparation of compound 19: Sodium hydride in oil (60% by wt, 1.088 g) was placed in a dry argon purged flask
equipped with a septum and stirbar. DMF (Aldrich, dry sure-seal™, 50 mL) was slowly
added to the ice-chilled flask. After the addition of the solvent, 6-nitroindole (compound
6, 4.01 g, 24.7 mmol) was added in portions over a 10 minute period. Stirring was continued
for an additional 15 minutes, followed by the addition of ethyl bromoacetate (3 mL,
27.2 mmol) via syringe. The solution was stirred at room temperature for 26 hours
and then quenched with distilled water (200 mL). The yellow precipitate which formed
was collected through filtration. The precipitate was washed with water (4 x 100 mL)
and the solid dried under reduced pressure to provide compound 19 (5.94 g, 97% yield); 1H NMR (CDCl3) δ: 8.25 (d, 1H, J=1.5), 8.05 (dd, 1H, J=1.5, 9), 7.70 (d, 1H, J=9), 7.38 (d, 1H,
J=3.3), 6.68 (d, 1H, J=3.3), 4.93 (s, 2H), 4.26 (q, 2H, J=7.2), 1.30 (t, 1H, J=7.2).
- (b) Preparation of compound 20: (6-Nitro-indol-1-yl)-acetic acid ethyl ester (compound 19, 503 mg, 2.026 mmol) was dissolved in dry toluene (30 mL). The mixture was cooled
to -78 °C in an acetone-dry ice bath under argon and the starting material began to
precipitate. A solution of DIBAL in toluene (1.5 mL, 1.1 eq) was added slowly down
the side of the flask and the mixture became homogenous. Stirring was continued for
2 hours at -78 °C. The reaction was quenched with methanol (1 mL) and then saturated
potassium sodium tartrate (20 mL) was added. The Mixture was transferred to a separatory
funnel and diluted with ethyl acetate (20 mL) and water (10 mL). The organic phase
was washed with potassium sodium tartrate (20 mL) and an additional 20 mL of brine
and 20 mL of ethyl acetate were added to break up the emulsion. The layers were separated
and the organic phase washed with brine (20 mL), dried over magnesium sulfate, filtered,
and concentrated under reduced pressure to afford a yellow solid. The solid was dissolved
in dichloromethane, preabsorbed onto silica gel (5 g), and purified via silica gel
column chromatography, using a packed column of 10 cm (height) by 3 cm (diameter)
using an eluant system of ethyl acetate and hexanes (30:70 - 2 column volumes, 1:1-2
column volumes) to provide compound 20, (366.5 mg, 88.6% yield); 1H NMR (CDCl3) δ: 5.04 (s, 2H), 6.71-6.73 (d, 1H), 7.36-7.37 (d, 1H), 7.68-7.73 (d, 1H), 8.02-8.07
(d, 1H), 8.18 (s, 1H), 9.79 (s, 1H); MS (APCI negative mode): 203.2.
- (c) Preparation of compound 21: (6 Nitro-indol-1-yl)-acetaldehyde (compound 20, 86.5 mg, 0.424 mmol) was placed in a small argon purged flask. A solution of 4-bromophenethylamine
(127 mg, 0.636 mmol) in dry methanol (3 mL) was added. The solution was stirred for
4.5 hours, followed by the addition of sodium triacetoxyborohydride (179 mg, 0.848
mmol). The solution was stirred at room temperature for an additional 24 hours. The
mixture was concentrated, the residue taken up in distilled water (5 mL) and ethyl
acetate (15 mL), and the biphasic mixture transferred to a separatory funnel. The
aqueous layer was washed with ethyl acetate (15 mL). The organic layers were combined,
washed with brine (5 mL), dried over MgSO4, filtered, and concentrated under reduced pressure. The product was dissolved in
CH2Cl2 and absorbed onto silica, which was subsequently dried and placed at the top of a
silica gel column. Elution of the column with 4:6 ethyl acetate/hexanes followed by
2.5% 2M NH3 in methanol/97.5% dichloromethane provided compound 21 as a brown solid (129.9 mg, 79% yield); 1H NMR (CDCl3) δ: 2.64-2.71 (t, 2H), 2.75-2.86 (t, 2H), 3.03-3.12 (t, 2H), 4.27-4.33 (t, 2H), 6.57-6.58
(d, 1H), 6.93-6.98 (d, 2H), 7.31-7.39 (t, 3H), 7.64-7.68 (d, 1 H), 8.00-8.05 (dd,
1H), 8.34 (s, 1H); MS: 388.0, 390.0 (M+1).
- (d) Preparation of compound 22: [2-(4-Bromo-phenyl)-ethyl]-[2-(6-nitro-indol-1-yl)-ethyl]-amine (compound 21, 53.5 mg, 0.138 mmol) was dissolved in anhydrous THF (2 mL) and cooled in an ice
bath. A solution of Boc2O (90 mg, 0.41 mmol) in THF (2 mL) was added followed by aqueous 2N NaOH (0.41 mL).
The solution was stirred at room temperature for 20.5 hours. The mixture was diluted
with water (20 mL) and ethyl acetate (20 mL) and transferred to a separatory funnel.
The aqueous layer was re-extracted with ethyl acetate (20 mL) and the combined organic
extracts were dried over MgSO4, filtered, and concentrated to afford compound 22 as a yellow oil (62.9 mg, 99% yield); 1H NMR (CDCl3) δ: 8.28 (br s, 1H), 8.00 (d, 1H, J = 2.0, 8.9), 7.65 (d, 1H, J = 8.9), 7.38-7.25
(m, 3H), 7.0-6.8 (m, 2H), 6.6 (d, 1H, J=3.2), 4.36-4.24 (m, 2H), 3.44 (m, 2H), 3.20
(m, 1H), 2.91 (m, 1H), 2.68 (m, 1H), 2.47 (m, 1H), 1.40 (s, 4.5H), 1.30 (4.5-) [note:
Boc conformational isomers were observed].
- (e) Preparation of compound 23: [2-(4-Bromo-phenyl)-ethyl]-[2-(6-nitro-indol-1-yl)-ethyl]-carbamic acid tert-butyl
ester (compound 22, 58.7 mg, 0.128 mmol) was placed in a small, argon purged flask fitted with a condenser
and magnetic stirbar. Tin (II) chloride dihydrate (143.8 mg, 0.637 mmol) was added
followed by absolute ethanol (10 mL). The solution was heated to reflux in an oil
bath for 24 hours, followed by cooling to room temperature. The reaction was diluted
with ethyl acetate (50 mL) and transferred to a separatory funnel. Aqueous 3N sodium
hydroxide solution was added and the organic phase collected. The organic phase was
washed with additional 3N NaOH (20 mL) followed by two brine washes (2 x 20 mL). The
organic phase was dried over magnesium sulfate, filtered, and concentrated to afford
a brown oil, which was purified using silica gel column chromatography to afford compound
23 as a light yellow oil (28.3 mg, 48% yield); H NMR (CDCl3) δ: 7.40-7.37 (m, 3H), 6.95-6.7 (m, 3H), 6.6-6.5 (m, 2H), 6.35 (d, 1H, J = 3.2),
4.18-3.95 (m, 2H), 3.61 (br s, 2H), 3.44-3.32 (m, 2H), 3.13-3.07 (m, 1H), 2.93-2.78
(m, 1H), 2.62 (m, 1H), 2.42 (m, 1H), 1.44 (s, 9H).
- (f) Preparation of compound 24: [2-(6-Amino-indol-1-yl)-ethyl]-[2-(4-bromo-phenyl)-ethyl]-carbamic acid tert-butyl
ester (compound 23, 24.5 mg, 0.053 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(24 mg, 0.080 mmol) were dissolved in ethanol (2 mL) in a small, argon purged flask.
The reaction was stirred under argon for 20 hours at room temperature. Additional
reagent was added (8 mg, 0.027 mmol) to ensure complete conversion of starting material
and stirring was continued for 24 hours. The solvent was evaporated and the product
was purified via silica gel column chromatography (2-5% 2M NH3 in methanol/ 98-95% dichloromethane). The product was dissolved in CH2Cl2 (2 mL) and 1 M HCl in ether (2 mL) was added, followed by stirring at room temperature.
The solvent was evaporated to afford compound 24 (5.7 mg, 21.4% yield).
Example 8: Preparation of Compound 27
[0204]
- (a) Preparation of compound 25: To an ice cold solution of 6-nitroindole (250 mg, 1.54 mmol) in DMF (8 mL) was added
sodium hydride (60% in oil suspension; 68 mg, 1.70 mmol) in one portion. The resulting
dark red solution was stirred at this temperature for 30 minutes and then (2-chloro-ethyl)-benzene
(0.60 mL, 2.31 mmol) was added. The reaction mixture was then heated to 110 °C for
5 hours. At this time, potassium carbonate (426 mg, 3.08 mmol) was added followed
by additional 2-chloroethylbenzene (0.30 mL, 2.31 mmol) and the mixture heated at
110 °C for 17 hours. The mixture was then removed from the bath and diluted with water
(20 mL) and extracted with ethyl acetate (100 mL). The organic layer was separated,
washed with brine, and dried over magnesium sulfate, filtered, and concentrated to
afford a brown residue. The residue was subjected to silica gel column chromatography
using a ethyl acetate/hexanes (10%:90%) to provide compound 25 (310 mg, 76% yield); 1H NMR (DMSO d6) δ: 8.42 (s, 1H), 7.88 (dd, 1H, J=1.5, 8.9), 7.71-7.69 (m, 2H), 7.24-7.16 (m, 5H),
6.61 (d, 1H, J=2.8), 4.60 (t, 2H, J=7.0), 3.10 (t, 2H, J=7.0).
- (b) Preparation of compound 26: A solution of 6-nitro-1-phenethyl-1H-indole (compound 25, 235 mg, 0.88 mmol) and tin (II) chloride dihydrate (995 mg, 4.41 mmol) in absolute
ethanol (10 mL) was heated to reflux in a small, argon purged flask fitted with a
condenser and magnetic stirbar. The solution was stirred for 6 hours, and then cooled
to room temperature. The reaction was diluted with aqueous 1N sodium hydroxide solution
(50 mL) and transferred to a separatory funnel. Ethyl acetate (100 mL) was added and
the organic phase washed with brine, dried over magnesium sulfate, and filtered through
a pad of silica gel. The filtrate was concentrated and purified via silica gel column
chromatography (1:1 ethyl acetate: hexanes) to provide compound 26 (180 mg, 86.6%); 1H NMR (DMSO d6) δ: 7.32-7.17 (m, 6H), 6.90 (d, 1H, J=3), 6.63 (s, 1H), 6.42 (dd, 1H, J=1.1, 8.5),
6.14 (d, 1H, J=3,), 4.19 (t, 2H, J=7.3), 3.01 (t, 2H, J=7.3); MS (APCI+): 237.0 (M+1).
- (c) Preparation of compound 27: A mixture of 1-phenethyl-1H-indol-6-ylamine (compound 26, 100 mg, 0.42 mmol) and thiophene-2-carboximidothioic acid phenyl ester hydrobromide
(254 mg, 0.85 mmol) was dissolved in anhydrous ethanol (4 mL) and stirred under argon
for 66 hours at room temperature. The reaction mixture was concentrated, diluted with
ethyl acetate (50 mL), and treated with saturated aqueous sodium bicarbonate (10 mL)
and water (20 mL). The organic layer was separated, washed with brine, dried over
magnesium sulfate, filtered, and concentrated to give a brown residue, which was purified
via silica gel column chromatography (5% 2M NH3 in methanol/ 95% dichloromethane). The product was dissolved in methanol (10 mL)
and 1 M aqueous HCl (2 mL) was added and stirred at room temperature. The solvent
was evaporated to provide compound 27 as a yellow solid (65 mg, 40.5% yield); 1H NMR (free base in CD3OD) δ: 7.66 (d, 1H, J=3.8), 7.58 (d, 1H, J=4.8), 7.53 (d, 1H, J=8.3), 7.20-7.13 (m,
4H), 7.08-7.06 (m, 2H), 6.99 (d, 1H, J=3.0), 6.73 (dd, 1H), 6.36 (d, 1H, 3.0), 4.36
(t, 2H, J=7.0), 3.09 (t, 2H, J=7.0); MS (APCI+): 346.4 (M+1).
Example 9: Preparation of Compounds 32 and 33
[0205]
- (a) Preparation of compounds 28 and 29: 6-Nitroindole (1.545 g, 9.52 mmol), 2-(2-chloroethyl)-1-methylpyrrolidine hydrochloride
(2.28 g, 12.4 mmol), and powdered potassium carbonate (2.55 g, 18.5 mmol) were placed
in an argon-purged two neck flask. DMF (20 mL, Aldrich sure seal™) was added and the
mixture heated to 65 °C in an oil bath for 46 hours. An additional amount of the 2-(2-chloroethyl)-1-methylpyrrolidine
hydrochloride (0.3 eq) was added and heating continued for an additional hour. The
solution was cooled to room temperature and diluted with water (50 mL) and ethyl acetate
(50 mL). The layers were separated and the aqueous phase extracted with ethyl acetate
(2 x 50 mL). The organic extracts were combined, washed with brine (2 x 50 mL), and
extracted with 1M HCl solution (20 mL, 15 mL, then 10 mL). The acidic fractions were
combined, made basic with 1N NaOH, extracted with ethyl acetate, washed with brine,
and dried over magnesium sulfate. The sample was filtered, concentrated, and the resultant
yellow oil purified via chromatography on silica (5% 2M ammonia/methanol in dichloromethane)
to give two compounds, compound 28 (1.087 g, 4.16 mmol, 43.7% yield); 1H NMR (CDCl3) δ: 1.43-1.67 (m, 1H), 1.71-1.97 (m, 4H), 2.12-2.32 (m, 6H), 3.06-3.10 (m, 1H), 4.24-4.32
(m, 2H), 6.62-6.63 (d, 1H), 7.42-7.43 (d, 1H), 7.66-7.68 (d, 1H), 8.01-8.04 (dd, Hz,
8.36-8.37 (d, 1H); MS (positive): 274.0 (M+1); and a rearranged product (compound
29, brown oil, 255 mg); 1H NMR (CDCl3) δ: 8.39 (s, 1H), 8.02 (dd, 1H, J = 1.5,6.6), 7.66 (d, 1H, J = 6.6), 7.55 (d, 1H,
J = 2.3), 6.62 (d, 1H, J = 2.3), 4.72-4.65 (heptet, 1H), 2.83-2.66 (m, 4H), 2.46 (s,
3H), 2.32-2.15 (m, 5 H), 2.03-1.95 (m, 1H), 1.90-1.80 (m, 1 H); MS (positive): 274.5
(M+1).
Resolution of enantiomers: To a solution of the racemic compound 28 (3.76 g, 13.76 mmol) in anhydrous ethanol (60 mL) was added a solution of dibenzoyl-L-tartaric
acid (2.46 g, 0.5 eq) in anhydrous ethanol (60 mL) with swirling. The resulting faintly
cloudy yellow solution was cooled for 24 hrs at 1°C. The yellow precipitate was collected
through vacuum filtration, washed with cold ethanol and ether, and dried under high
vacuum overnight to yield 4.1 g of a granular yellow solid The filtrate was concentrated
to afford a residue. Both the precipitate and the filtrate residue were converted
to free base in parallel as follows: The crude enantiomer was partitioned between
ethyl acetate and water and the pH adjusted to 8 with saturated sodium hydrogen carbonate.
The aqueous phase was extracted twice more with ethyl acetate. The combined organics
were washed with brine, dried over magnesium sulfate, filtered, and concentrated.
The residue was dried under high vacuum at for 3 hours at 75 °C, followed by further
drying overnight at room temperature. Both enantiomers were brown oils; L-enantiomer,
compound 28(-) (2.42 g from the crystalline fraction using L-dibenzoyltartaric acid); [αd]20 (methanol) = -12.950°; and D-enantiomer, compound 28(+) (filtrate residue, 1.229 g), [αd]20 (methanol) = +25.416°.
L-enantiomer enrichment: The enriched L-enantiomer (compound 28(-), 2.42 g, 6.88 mmol) was dissolved in ethanol (37 mL) and a solution of dibenzoyl-L-tartaric
acid (1.232 g, 3.44 mmol) in ethanol (37 mL) added with swirling, resulting in a faintly
cloudy orange-yellow solution. The solution was kept at room temperature for 1 hr
and then overnight at 1 °C. The solid was collected by filtration, washed with ethanol,
followed by washing with ether, and the solid dried under high vacuum at room temperature
for 3 hrs to yield 2.75 g of a yellow solid, mp 99-110 °C. The solid was recrystallized
from hot ethanol (70 mL total volume) and allowed to cool to room temperature followed
by cooling to 1 °C for 44 hrs. The solid was collected by filtration, washed with
cold ethanol and then cold diethylether, dried under high vacuum to yield a yellow
solid (1.55 g, mp 99-110 °C). The solid was partitioned between ethyl acetate (100
mL) and water (50 mL) and the pH adjusted to 8-9 using saturated sodium bicarbonate
solution. The layers were separated and the aqueous layer extracted with ethyl acetate
(twice). The combined organic layers were washed with brine, dried over magnesium
sulfate and concentrated to yield a brown oil. The oil was dried under high vacuum
at room temperature overnight to provide compound 28(-) enantiomer (0.969 g); [αd]20 (methanol) = -38.64°; 1H NMR (CDCl3) δ: 1.59-1.47 (m, 1H), 2.00-1.79 (m, 4H), 2.24-2.15 (m 3H), 2.31 (s, 3H), 3.13-3.08
(m, 1H), 4.35-4.19 (m, 2H), 6.60 (d, 1H, J = 3.0), 7.41 (d, 1H, J = 3.2), 7.65 (d,
1H, J = 8.8), 7.99 (dd, 1H, J = 8.93, 1.91), 8.35 (s, 1H).
D-enantiomer enrichment: In a manner similar to the enrichment of the L-enantiomer,
compound 28(+) was prepared using D-(+)-dibenzoyltartaric acid to yield 0.898 g of a brown oil;
[αd] 20 (methanol) = +40.52°; 1H NMR (CDCl3) δ: 8.34 (d, 1H, J = 1.5), 8.1 (1H, dd, J = 1.8,8.4), 7.66 (d, 1I-L J = 8.7), 7.40
(d, 1H, J = 3), 6.60 (d, 1H, J = 3), 4.37-4.19 (m, 2H), 3.12-3.07 (m, 1H), 2.31 (s,
3H), 2.28-2.15 (m, 3H), 2.02-1.70 (m, 4H), 1.59-1.51 (m, 1H).
- (b) Preparation of compound 30: Racemic 1-[2-(1-Methyl-pyrrolidin-2-yl)-ethyl]-6-nitro-1H-indole (compound 28, 727 mg, 2.66 mmol) and tin (II) chloride dihydrate (2.017 g, 10.67 mmol) were placed
in a small flask fitted with a condenser and magnetic stirbar. Absolute ethanol (10
mL) was added and the solution was heated to reflux in an oil bath for 24 hours, followed
by cooling to room temperature. The mixture was diluted with ethyl acetate (50 mL)
and transferred to a separatory funnel. An aqueous 3N sodium hydroxide solution (50
mL) was added and the organic fraction collected. Precipitate present in the funnel
was removed with the aqueous layer. The organic phase was washed twice with additional
3N NaOH (20 mL), followed by two brine washes (2 x 20 mL). The organic phase was dried
over sodium sulfate, filtered, and concentrated to give a black oil, which was purified
via silica gel column chromatography (5% 2M NH3 in Methanol/95% dichloromethane) to afford racemic compound 30 (472.3 mg, 73% yield) as a brownish oil; 1H NMR (CDCl3) δ: 1.41-1.59 (m, 1H), 1.71-1.79 (m, 3H), 1.86-1.98 (m, 1H), 2.05-2.16 (m, 3H), 2.29
(s, 3H), 3.03-3.06 (t, 1 H), 3.63 (bs, 2H, -NH2), 4.00-4.08 (m, 2H), 6.35-6.36 (d, 1H), 6.54-6.55 (d, 1H) 6.56-6.57 (d, 1H), 6.90-6.91
(d, 1H), 7.38-7.40 (d, 1H).
Preparation of compound 30(-): To an argon purged flask containing the enantiomerically resolved 1-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-6-nitro-1H-indole
(compound 28(-), 969 mg, 3.545 mmol) and a magnetic stir bar was added anhydrous ethanol (75 mL).
While stirring, palladium on carbon (10%, 283 mg, 0.266 mmol) was added quickly in
portions and the atmosphere evacuated and replaced with hydrogen using a balloon/aspirator
system. The system was evacuated a total of 3 times to ensure that no residual oxygen
remained. The mixture was stirred at room temperature for 3 hrs. The hydrogen atmosphere
replaced with argon via a purge/fill operation, the mixture filtered through celite,
and the solid washed with absolute ethanol (25 mL). The collection flask was sealed
and purged with argon and used crude in the next reaction for the synthesis of compound
32(-).
Preparation of compound 30(+): In a manner similar to the preparation of compound 30(-) from compound 28(-), compound 28(+) (870 mg, 3.183 mmol) was used to prepare compound 30(+). After filtration through celite, the crude solution of compound 30(+) in ethanol was used for the preparation of optically pure compound 32(+).
Preparation of compound 31: In a manner similar to the preparation of compound 30 from compound 28, compound 31 was synthesized from compound 29 (190 mg, 0.695 mmol). After filtration through celite, the crude solution of compound
31 was used directly in the preparation of compound 33.
- (c) Preparation of racemic compound 32: 1-[2-(1-Methyl-pyrrolidin-2-yl)-ethyl]-1H-indol-6-ylamine (compound 30,47.9 mg, 0.197 mmol) was dissolved in ethanol (3 mL) in a small, argon purged flask.
Thiophene-2-carboximidothioic acid phenyl ester hydrobromide (76.9 mg, 0.256 mmol)
was added and the solution was stirred at room temperature for 48 hours. The solvent
was evaporated and the product was purified via silica gel column chromatography (5%
2M NH3 in methanol/95% dichloromethane) to afford the free base of compound 32 as a yellow oil (52.5 mg, 75% yield). The free base was dissolved in methanol (2
mL), treated with 1M HCl, followed by evaporation to dryness to provide the HCl salt
of compound 32 as a reddish (salmon) coloured solid (54.8, 95.1% yield); 1H NMR (free base, CDCl3) δ: 1.67-1.78 (m, 1H), 1.93-1.98 (m, 2H), 2.04-2.19 (m, 4H), 2.26 (s, 3H), 3.00-3.05
(t, 1H), 4.05-4.12 (m, 2H), 4.86 (s, 2H), 6.43-6.44 (d, 1H), 6.76-6.78 (d, 1H), 6.96
(s, 1H), 7.02-7.03 (d, 1H), 7.05-7.07 (t, 1H), 7.40-7.41 (d, 2H), 7.52-7.57 (d, 1H);
MS (positive): 353.2 (M+1).
Preparation of compound 32(-): To an argon purged flask containing crude enantiomerically-resolved 1-[2-(1-methyl-pyrrolidin-2-yl)-ethyl]-1H-indol-6-ylamine
(compound 30(-), 3.545 mmol) in anhydrous ethanol (100 mL) was added a magnetic stirbar, followed
by the addition of thiophene-2-carboximidothioic acid methyl ester hydroiodide (1.213
g, 1.2 eq). After stirring at room temperature for 24 hours, additional thiophene
reagent (0.202 g, 0.2 eq) was added. After an additional 18 hours, the reaction was
concentrated and the residue partitioned between ethyl acetate (100 mL), water (50
mL), and saturated sodium hydrogen carbonate (50 mL). The aqueous layer was checked
and found to be a pH of 8. The aqueous layer was extracted twice more with ethyl acetate
and the combined organics were washed successively with saturated sodium hydrogen
carbonate and brine, filtered, and concentrated to yield an orange-brown oil (1.56
g). The crude product was purified via dry column chromatography (5% 2M NH3 in methanol/95% dichloromethane) with 17x100 mL aliquots to yield compound 32(-) as a yellow oil (0.63 g). The HCl salt was formed by dissolving the product in
anhydrous dichloromethane (10 mL) and adding 1M HCl in ether (5.36 mL, 3 eq) under
argon; 1H NMR (free base, CDCl3) δ: 1.50-1.52 (m, 1H), 1.67-1.82 (m, 4H), 1.92-1.95 (m, 1H), 2.07-2.15 (m, 3H), 2.28
(s, 3H), 3.06 (t, 1H), 4.02-4.12 (m, 2H), 4.87 (s, 2H), 6.45-6.46 (d, 1H), 6.78-6.81
(d, 1H), 6.98 (s, 1H), 7.04-7.05 (d, 2H), 7.43-7.45 (d, 2H), 7.57-7.59 (d, 1H); MS
(positive): 353.5 (M+1).
Preparation of compound 32(+): Similar to the preparation of compound 32(-) from compound 30(-), compound 30(+) was used to prepare compound 32(+) as a yellow oil (0.715 g) which was converted to a hydrochloride salt with excess
1M HCl in ether; 1H NMR (free base, CDCl3) δ: 1.49-1.57 (m, 1H), 1.71-1.82 (m, 4H), 1.89-1.95 (m, 1H), 2.07-2.15 (m, 3H), 2.29
(s, 3 H), 3.04-3.06 (t, 1H), 4.07-4.15 (m, 1H), 4.87 (s, 2H), 6.45-6.46 (d, 1H), 6.78-6.81
(d, 1H), 6.98 (s, 1H), 7.04-7.09 (m, 2 H), 7.43-7.45 (d, 2H), 7.57-7.59 (d, 1H); MS
(positive): 353.5 (M+1).
Preparation of compound 33: In a manner similar to the preparation of compound 32 from compound 30, compound 31 was used to prepare the free base of compound 33 as a pale pink solid (107 mg, 0.304 mmol). The hydrochloride salt was prepared by
dissolving the crude solid (107 mg) in anhydrous dichloromethane (5 mL) followed by
the addition of 1M HCl in ether (3 eq. 0.91 mL). The pale green/beige solid which
precipitated immediately was collected and washed with a small amount of dichloromethane
and dried under high vacuum to yield the hydrochloride salt as a pale brown solid
(92 mg as the dihydrochloride); 1HNMR (HCl salt, DMSO-d6) δ: 11.55 (br s, 1H), 11.18 (br s, 1H), 9.74 (br s, 1H), 8.74
(br s, 1H), 8.18 (m, 2H), 7.77-7.70 (m, 3H), 7.40 (3 line m, 1H), 7.06 (d, 1H, J=7.8
Hz), 6.62 (s, 1H), 4.94-4.77 (m, 1H), 3.48-3.17 (m, 4H), 2.78 (s, 3H), 2.26-1.95 (m,
6H); MS (pos): 353.5.
Example 10: Preparation of Compound 37
[0206]
- (a) Preparation of compound 34: (6-Nitro-indol-1-yl)-acetic acid ethyl ester (compound 19, 3.06 g, 12.3 mmol) was dissolved in THF (60 mL, Aldrich Sure Seal™). The solution was cooled to -78 °C in an acetone-dry ice bath under argon and a
solution of DIBAL in toluene (18.9 mL, 2.3 eq) was added slowly down the side of the
flask. The reaction was stirred for 44.5 hrs at room temperature, after which the
brown solution was quenched with 3N sodium hydroxide (20 mL). The mixture was transferred
to a separatory funnel and diluted with ethyl acetate (50 mL) and water (20 mL). The
layers were shaken, separated, and the aqueous phase extracted with ethyl acetate
(20 mL). The combined organics were washed with brine (20 mL), dried over magnesium
sulfate, treated with charcoal, filtered, and concentrated to afford a brownish-yellow
solid (2.10 g). The crude product was dissolved in ethyl acetate, pre-absorbed onto
silica gel, and purified via silica gel column chromatography (3:7 ethyl acetate and
hexanes) to provide compound 34 as a yellow solid (1.18 g, 61% yield).
- (b) Preparation of compound 35: 2-(6-Nitro-indol-1-yl)-ethanol (compound 34, 1.1791 g, 5.72 mmol) was placed in a small argon purged flask and dissolved in dry
THF (20 mL). Triethylamine (1.6 mL, 1.5 eq) was added, followed by the addition of
methanesulfonyl chloride (0.63 mL, 1.43 eq). A precipitate began forming immediately.
The mixture was stirred at room temperature under argon for 48 hrs. The reaction was
concentrated to afford a yellow solid. DMF (15 mL) and piperidine (10 mL) were added
and the solution was heated to 110 °C and stirred for 21 hrs. The dark yellow solution
was cooled to room temperature, transferred to a separatory funnel, and diluted with
water (75 mL) and ethyl acetate (25 mL). The aqueous layer was extracted with ethyl
acetate (3 x 25 mL) and the combined organic layers were washed with brine (3 x 25
mL). The organic phase was then treated with 1M hydrochloric acid (50 mL), resulting
in a yellow precipitate. The precipitate was removed through filtration and the filtrate
treated with additional hydrochloric acid (25 mL). The layers were separated after
shaking, and the aqueous phase made basic with 10% sodium hydroxide solution. The
cloudy mixture was extracted with ethyl acetate (3 x 20 mL). The combined organics
were washed with brine, dried over MgSO4, filtered, and concentrated. The product was purified via silica gel column chromatography
(2.5% 2M NH3 in methanol/97.5% dichloromethane), followed by recrystallization from ethanol to
give compound 35 as a yellow solid (1.029 g, 66% yield); 1H NMR (CDCl3) δ: 8.37 (s, 1H), 7.98 (dd, 1H, J=1.67, 8.8), 7.62 (d, 1H, J=8.8), 7.44 (d, 1H, J=3.3),
7.25 (s, 1H), 6.56 (d, 1H, J=3.0), 4.28 (t, 2H, J=6.7), 2.70 (t, 2H, J=6.7), 2.43
(t, 4H, J=4.9), 1.59-1.55 (m, 4H), 1.45-1.40 (m, 2H).
- (c) Preparation of compound 36: 6-Nitro-1-(2-piperidin-1-yl-ethyl)-1H-indole (compound 35, 1.029 g, 3.76 mmol) and 10% palladium on carbon (111 mg) were placed in a large,
argon purged flask. Absolute ethanol (20 mL) was added, and the atmosphere was replaced
with hydrogen using a balloon/aspirator system. The mixture was stirred at room temperature
for 18.5 hrs. The solution was treated with charcoal and filtered through celite (2
cm pad) and washed through with absolute ethanol (30 mL). The flask was sealed and
purged with argon and used crude in the next reaction.
- (d) Preparation of compound 37: To the crude solution of 1-(1-(2-piperidin-1-yl-ethyl)-1H-indol-6-ylamine (compound
36, 3.76 mmol) in absolute ethanol (50 mL) was added thiophene-2-carboximidothioic acid
phenyl ester hydrobromide (1.185 g, 1.05 eq). The reaction was stirred under argon
for 24 hours at ambient temperature. An additional 0.1 eq of the thiophene reagent
was added and the reaction stirred for a further 24 hours. The solvent was evaporated
and the oil diluted with a small amount of ethanol (<5 mL) followed by diethyl ether
to afford a yellow precipitate. The solid was isolated through filtration and washed
with ether. The precipitate was dried under suction followed by additional drying
under high vacuum to give compound 37 as the HBr salt (yield 983.2 mg). The free base was obtained by dissolving the solid
in water (35 mL) and adding 1N sodium hydroxide (10 mL). The product was extracted
into ethyl acetate (2 x 30 mL). The combined organics were dried over MgSO4, filtered, and concentrated to afford compound 37 as a light yellow solid (708 mg); 1H NMR (CDCl3) δ: 7.57 (d, 1H, J=8.3), 7.43 (m, 2H), 7.09 (m, 2H), 6.99 (s, 1H), 6.79 (d, 1H, J=7.6),
6.44 (d, 1H, J=3.0), 4.87 (br s, 2H), 4.20, (t, 2H, J=7.5), 2.71 (t, 2H, J=7.6), 2.45
(br s, 4H), 1.62-1.58 (m, 6H) 1.46-1.40 (m, 2H).
Example 11. Preparation of N-(3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(42) and N-(3-(1-methylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (43):
[0207]
[0208] 3-(1-Methyl-1,2,3,6-tetrahydro-pyridin-4-yl)-5-nitro-1H-indole (39): A solution of 5-nitroindole (
38) (0.5 g, 3.083 mmol) in dry ethanol (5 mL) was treated with pyrrolidine (0.77 mL,
9.250 mmol),
N-methyl-4-piperidone (0.75 mL, 6.167 mmol) at room temperature. The resulting solution
was refluxed for 2 days. The reaction was brought to room temperature, the solid was
filtered off, washed with ethanol (2 × 5 mL) and dried to obtain compound (
39) (0.591 g, 75%). Solid decomposed at 215 °C;
1H NMR (DMSO-
d6) δ 2.29 (s, 3H), 2.50-2.59 (m, 4H), 3.06-3.08 (m, 2H), 6.17 (br s, 1H), 7.55 (d,
1H,
J = 9.0 Hz), 7.66 (s, 1H), 8.01 (dd, 1H,
J = 2.1, 9.0 Hz), 8.68 (d, 1H,
J = 2.1 Hz), 11.86 (brs, 1H).
[0209] N-(3-(1-methyl-1,2,3,6-tetrahydro-pyridin-4-y1)-1H-indol-5-yl]-thiophene-2-carboxamidine
(40) and N-[3-(1-methyl-piperidin-4-yl)-1H-indol-5-yl]-thiophene-2-carboxamidine (41): A solution of compound
39 (0.4 g, 1.554 mmol) in dry methanol ( 5 mL) was treated with Ra-Ni (0.1 g), followed
by hydrazine hydrate (0.48 mL, 15.546 mmol) at room temperature and the resulting
solution was stirred at 65 °C for 3 h. The reaction was brought to room temperature,
solid was filtered off though celite bed and washed with methanol: CH
2Cl
2 (1:1, 2 × 10 mL). The combined organic layer was evaporated and crude was purified
by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain the free amine (0.35 g, quantitative) as a foam. A solution of the
amine (0.18 g, 0.791 mmol) in dry ethanol (10 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.45 g, 1.583 mmol) at room temperature and the mixture
was stirred for 24 h. The solvent was evaporated and product was precipitated with
ether (100 mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 30 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95 to 1:9) to obtain compound
40 (0.165 g, 62%) and
41 (0.02 g, 8%). Compound
40: Solid, mp 203-205 °C;
1H NMR (DMSO-
d6) δ 2.26 (s, 3H), 2.50-2.56 (m, 4H), 3.00-3.02 (m, 2H), 6.04 (s, 1H), 6.23 (brs, 1H),
6.66 (dd, 1H,
J = 1.2, 8.8 Hz), 7.09 (dd, 1H,
J = 3.9, 5.1 Hz), 7.21 (s, 1H), 7.31 (dd, 2H,
J = 2.4, 5.4 Hz), 7.59 (d, 1H,
J = 4.2 Hz), 7.71 (d, 1H,
J = 3.6 Hz), 10.93 (s, 1H); ESI-MS m/z (%): 337 (M
+, 100); Compound
41: Solid, mp 148-150 °C;
1H NMR (DMSO-
d6) δ 1.62-1.79 (m, 2H), 1.90-1.94 (m, 2H), 2.04-2.12 (m, 2H), 2.23 (s, 3H), 2.63-2.72
(m, 1H), 2.86-2.89 (m, 2H), 6.28 (brs, 1H), 6.63 (dd, 1H,
J = 1.8, 8.7 Hz), 6.98 (s, 1H), 7.02 (d, 1H,
J = 2.1 Hz), 7.09 (dd, 1H,
J = 3.9, 5.1 Hz), 7.27 (d, 1H,
J = 8.4 Hz), 7.59 (d, 1H,
J = 5.1 Hz), 7.71 (d, 1H,
J = 3.6 Hz), 10.60 (s, 1H); ESI-MS m/z (%):: 339 (M
+, 100).
[0210] Dihydrochloride salt of N-[3-(1-methyl-1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indol-5-yl]-thiopheme-2-carboxamidine
(42): A solution of compound
40 (0.155 g, 0.460 mmol) in ethanol (5 mL) was treated with 1 N HCl in ether (1.5 mL)
at room temperature and stirred for 1 h. The product was recrystallized from ethanol/ether
to obtain compound
42 (0.13 g, 69%) as a solid. mp 215-218 °C.
[0211] Dihydrochloride salt of N-[3-(1-methyl-piperidin-4-yl)-1H-indol-5-yl]-thiophene-2-carboxamidine (
43): A solution of compound
41 (0.015 g, 0.044 mmol) in ethanol (3 mL) was treated with 1 N HCl in ether (0.13 mL)
at room temperature and stirred for 1 h. The product was recrystallized from ethanol/ether
to obtain compound
43 (0.012 g, 67%) as a foam.
Example 12. N-(3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)furan-2-carboximidamide
(46) and N-(3-(1-methylpiperidin-4-yl)-1H-indol-5-yl)furan-2-carboximidamide (47):
[0212]
[0213] 3-(1-Methyl-1,2,3,6-tetrahydro-pyridin-4-yl)-5-nitro-1H-indole (39): Please see Example 11 for experimental details.
[0214] N-[3-(1-Methyl-1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indol-5-yl]-furan-2-carboxamidine
(44) and
N-[3-(1-methyl-piperidin-4-yl)-1H-indol-5-yl]-furan-2-carboxamidine
(45): A solution of compound
39 (0.4 g, 1.554 mmol) in dry methanol (5 mL) was treated with Ra-Ni (0.1 g), followed
by hydrazine hydrate (0.48 mL, 15.546 mmol) at room temperature and the resulting
solution was stirred at 65 °C for 3 h. The reaction was brought to room temperature,
solid was filtered off though celite bed and washed with methanol: CH
2Cl
2 (1:1, 2 × 10 mL). The combined organic layer was evaporated and crude was purified
by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain the free amine (0.35 g, quantitative) as a solid. A solution of the
amine (0.17 g, 0.747 mmol) in dry ethanol (10 mL) was treated with benzyl furan-2-carbimidothioate
hydrobromide (0.44 g, 1.495 mmol) at room temperature and stirred for 24 h. The solvent
was evaporated and product was precipitated with ether (100 mL). The solid was dissolved
into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 30 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95 to 1:9) to obtain compound
44 (0.16 g, 67%) and
45 (0.02 g, 8%). Compound
44: Solid, mp 161-163 °C;
1H NMR (DMSO-
d6) δ 2.28 (s, 3H), 2.50-2.57 (m, 4H), 3.03-3.05 (m, 2H), 6.04 (s, 1H), 6.63 (s, 1H),
6.73 (d, 1H,
J = 8.1 Hz), 7.15 (s, 1H), 7.31-7.34 (m, 3H), 7.82 (s, 1H), 10.99 (s, 1H); ESI-MS m/z
(%): 321 (M
+, 100). Compound
45: Solid, mp 85-87 °C;
1H NMR (DMSO-
d6) δ 1.81-1.90 (m, 2H), 1.99-2.03 (m, 2H), 2.40-2.60 (m, 5H), 2.81-2.88 (m, 1H), 3.12-3.15
(m, 2H), 6.81 (s, 1H), 6.93 (d, 1H,
J = 8.4 Hz), 7.20 (s, 1H), 7.41-7.47 (m, 3H), 7.58 (brs, 1H), 8.09 (s, 1H), 11.01 (s,
1H); ESI-MS m/z (%): 323 (M
+, 100).
[0215] Dihydrochloride salt of N-[3-(1-methyl-1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indol-5-yl]-furan-2-carboxamidine
(46): A solution of compound
44 (0.145 g, 0.452 mmol) in ethanol (5 mL) was treated with 1 N HCl in ether (1.35 mL)
at room temperature and stirred for 1 h. The product was recrystallized from ethanol/ether
to obtain compound
46 (0.135 g, 76%) as a solid. mp 212-215 °C.
[0216] Dihydrochloride salt of N-[3-(1-methyl-piperidin-4-yl)-1H-indol-5-yl]-furan-2-carboxamidine (47): A solution of compound
45 (0.015 g, 0.046 mmol) in ethanol (2 mL) was treated with 1 N HCl in ether (0.14 mL)
at room temperature and stirred for 1 h. The product was recrystallized from ethanol/ether
to obtain compound
47 (0.01 g, 56%) as a foam.
Example 13. N-((3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)methyl)thiophene-2-carboximidamide
(51):
[0217]
3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indole-5-carbonitrile (49):
[0218] To an argon-purged round bottom flask fitted with a magnetic stirbar containing an
orange solution of 5-cyanoindole
(48) (250 mg, 1.76 mmol) dissolved in absolute ethanol (10 mL) were added 1-methyl-4-piperidone
(0.43 mL, 3.50 mmol) and pyrrolidine ( 0.44mL, 5.27 mmol). The reaction vessel was
fitted with a condenser and transferred to an oil bath preheated to 80°C. The reaction
was stirred at this temperature for 44 hrs. As no starting material remained (TLC
5% 2M NH
3 in mcthanol/95% CH
2Cl
2) the reaction was cooled to room temperature followed by additional cooling in the
fridge. As no precipitate formed, the reaction was concentrated under reduced pressure
to afford an orange oil. The oil was redissolved in ethanol (20 mL) and the solvent
removed under reduced pressure. This was repeated once more, and then the final residue
was treated with ethanol and left in the fridge for 2 hrs. The precipitate which formed
was collected by vacuum filtration and washed with hexanes (205 mg of pale yellow
solid, compound
49, 48.7%)
1H NMR (DMSO) δ 11.90 (br s, NH), 8.51 (s, 1H), 7.80 (s, 1H), 7.77-7.74 (d, J = 8.7
Hz , 1H), 7.68-7.65 (d, J = 8.1 Hz, 1 H), 6.41 (s, 1H), 3.53 (s, 2H), 3.27-3.26 (d,
J = 2.4 Hz, 2H), 2.79-2.77 (d, J = 4.5 Hz, 2H), 2.72-2.71 (d, J = 1.5Hz, 3H).
(3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)methanamine (50):
[0219] To an argon purged round bottom flask fitted with a condenser and magnetic stirbar
containing
49 (105 mg, 0.442 mmol) was added lithium aluminum hydride (34 mg, 0.896 mmol) followed
by absolute THF (5 mL). A small amount of gas was produced. Once no more bubbling
occurred, the reaction was transferred to an oil bath heated to 75°C. The reaction
was stirred at this temperature for 18 hrs. The reaction was then cooled to room temperature.
The reaction was quenched with water (0.1 mL), 3N NaOH (0.1 mL) and water (0.3 mL)
sequentially, followed by filtration through a celite plug. The plug was washed with
THF and the filtrate concentrated to afford a yellow oil, compound
50 (106 mg, 99%).
1H NMR (DMSO) δ 10.95 (br s, NH), 7.74 (s, 1H), 7.32-7.31 (d, J = 2.4 Hz, 1H), 7.30-7.27
(d, J = 8.4Hz, 1H), 7.08-7.05 (d, J = 8.1 Hz, 1H), 6.14 (s, 1H), 3.77 (s, 2H), 3.29
(s, 2H), 3.06-3.05 (d, J=2.7 Hz, 2H), 2.57-2.56 (d, J = 4.5 Hz, 2H), 2.51-2.50 (d,
J = 1.2Hz, 2H), 2.29 (s, 3H), 1.75 (br s, 2NH).
N-((3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)methyl)thiophene-2-carboximidamide
dihydrochloride (51):
[0220] An Ar purged 20 mL reaction vial fitted with a magnetic stirbar containing a solution
of compound
50 (58 mg, 2.55 mmol) and thiophene-2-carboximidothioic acid methyl ester hydroiodide
(145 mg, 5.08 mmol) in absolute ethanol (5 mL) was stirred at room temperature for
41 hrs. As all starting material had reacted (20% 2M NH
3 in methanol/80%CH
2Cl
2) the reaction was concentrated to dryness under reduced pressure. The residue was
partitioned between ethyl acetate (10 mL) and 3N NaOH (10 mL) followed by transfer
to a separatory funnel. The aqueous phase was extracted twice more with ethyl acetate
(2x10 mL). The combined organics were washed with brine, dried over MgSO4, filtered
and concentrated to afford a pale yellow solid (35 mg). The product was absorbed onto
silica gel and purified by column chromatography (25-50% 2M NH
3 in methanol/CH
2Cl
2) to afford a pale yellow solid (23 mg) The product was taken up in methanol and treated
with 1M HCl in ether. The reaction was stirred for 25 minutes and then concentrated
to dryness under reduced pressure. The residue was taken up in ethanol (3mL) and diluted
with ether (35 mL) to afford a precipitate that was collected by filtration. The precipitate
was washed with ether (2x10 mL) and dried under high vacuum. Yield: 17 mg of pale
yellow solid, compound
51 (21 %).
1H NMR (free base in DMSO-
d6) δ 11.04 (br s, NH), 7.86 (s, 1H), 7.68-7.67 (d, J=3.9Hz, 1H), 7.64 (s, 1H), 7.36-7.35(d,
J=2.7Hz, 1H), 7.32 (s, 1H), 7.15-7.14 (d, J=1.2, 1H), 7.13-7.11 (t, J=4.2, 1H), 6.13
(s, 1H), 4.47 (s, 2H), 3.31 (s, 2H), 3.05-3.04 (d, J=2.7Hz, 2H), 2.58-2.56 (d, J=4.5Hz,
2H), 2.29 (s, 3H); ESI-MS m/z (%): 351 (M+, 100).
Example 14. N-(3-(3-(dimethylamino)propyl)-1H-indol-5-yl)thiophene-2-carboximidamide (56):
[0221]
3-(5-Bromo-1H-indol-3-yl)-N,N-dimethylpropanamide (53):
[0222] To a 250 mL argon purged round bottom flask fitted with a magnetic stirbar containing
a yellow solution of 5-bromo-indol-3-propionic acid
(52) (3.00 g, 11.19 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride
(2.36 g, 12.31 mmol), 1-hydroxybenzotriazole (1.51g, 11.17 mmol) and dimethylamine
hydrochloride (912 mg, 11.19 mmol) in DMF (20 mL) was added triethylamine (4.7 mL,
25.83 mmol) resulting in the formation of a precipitate. The reaction was monitored
by TLC (1:1 ethyl acetate, hexane). After 2 hours the argon purge needle was removed
and additional dimethylamine hydrochloride added (0.3 eq). After a total of 20 hours,
TLC revealed complete consumption of starting material. The reaction was diluted with
water (40 mL) and ethyl acetate (40 mL). The reaction was transferred to a separatory
funnel and the product was extracted into the organic layer. The organic layer was
extracted again with water (20 mL) to remove the DMF, followed by 2 N NaOH (20 mL)
and brine (15 mL). The yellow organic layer was dried over magnesium sulfate, filtered
and concentrated to afford a white-pink solid. The product was purified by silica
gel column chromatography (9:1 Ethyl acetate/hexanes) Yield: 1.407 g pure, compound
53, 1H NMR (DMSO) δ 11.00 (br s, NH), 7.68-7.67 (d, 1H, J = 1.5), 7.31-7.28 (d, 1H, J =
8.4 Hz), 7.72-7.14 (td, 2H,
J= 1.8, 8.4 Hz), 2.93-2.81 (m, 8 H), 2.64 - 2.59 (t, J = 7.5 Hz, 2H).
3-(5-Bromo-1H-indol-3-yl)-N,N-dimethylpropan-1-amine (54):
[0223] To an argon purged 250 mL round bottom flask fitted with condenser and magnetic stirbar
containing
53 (1.283 g, 4.35 mmol) was added lithium aluminum hydride (412 mg, 10.86 mmol). Anhydrous
tetrahydrofuran (15 mL) was added resulting in gas formation. The flask was placed
in an oil bath and heated to 65°C and stirred for 16 hours under argon. The reaction
was cooled to room temperature and quenched with water (1.1 mL), 3N sodium hydroxide
(1.7 mL) and water (3.3 mL) sequentially. The mixture was filtered to remove the white
solid and the pale yellow filtrate concentrated to afford a pale yellow oil. Drying
under high vacuum afforded a pale yellow solid, compound
54. Yield: 1.193 g of pale yellow solid (97.5%).
1H NMR (DMSO) δ 7.65-7.64 (d, 1H, J = 1.5), 7.30-7.27 (d, 1H, J = 8.7 Hz), 7.167 (s,
1 H), 7.14-7.09 (q, 1H,
J= 6.9, 8.4 Hz), 2.67-2.62 (t, J = 7.5, 2H), 2.25 - 2.20 (t, J = 7.5 Hz, 2H), 2.12
(s, 8 H).
3-(3-(Dimethylamino)propyl)-1H-indol-5-amine (55):
[0224] To an argon purged vial fitted with a magnetic stirbar and containing
54 (324 mg, 1.15 mmol) was cannulated a solution of Pd
2(dba)
3 (53 mg, 0.058 mmol), and Tri-t-butyl phosphine solution (0.34 mL, 10%, 0.11 mmol)
in dry THF (8 mL). The flask was fitted with a condenser and a 1M solution of lithium
hexamethyldisilane in THF (3.45 mL, 3.45 mmol) was added. The reaction was placed
in a metal heating block and heated to reflux. The reaction was stirred at this temperature
for 16 hours. TLC (10% 2M ammonia in methanol, 90% dichloromethane) revealed all starting
material had reacted. The reaction was cooled to room temperature and quenched with
1M aqueous hydrogen chloride (15 mL). The acidic reaction was extracted with ethyl
acetate (3 x 10 mL). The aqueous phase was basified with 3N sodium hydroxide (8 mL)
and partitioned into ethyl acetate (3 x 10 mL). The organics were washed with brine,
dried over magnesium sulfate, and treated with charcoal. Filtration through celite,
concentration and further drying under high vacuum afforded a dark yellow oil. Purification
of the product was performed using silica gel column chromatography (5-10% 2M ammonia
in methanol, 95-90% dichloromethane) Yield: 162 mg of brown oil, compound
55 (65%).
1H NMR (CDCl3) δ 7.76 (br s, NH), 7.17-7.14 (d, 1H, J = 8.4 Hz), 6.92-6.90 (dd, 2H,
J = 2.1,4.5 Hz), 6.67 - 6.64 (dd, 1 H, J = 2.1, 8.4 Hz), 2.73-2.68 (t, J = 7.5,2H),
2.41 - 2.36 (t, J = 7.5Hz, 2H), 2.26 (s, 8H).
N-(3-(3-(dimethylamino)propyl)-1H-indol-5-yl)thiophene-2-carboximidamide (56):
[0225] To an argon purged round bottom flask containing
55 (340 mg, 1.56 mmol) was added thiophene-2-carboximidothioic acid methyl ester hydroiodide
(669 mg, 2.35 mmol). The two were suspended in absolute ethanol (10 mL) and stirred
at room temperature for 16 hours. TLC (10% 2M ammonia in methanol, 90% dichloromethane)
revealed all amine had reacted. The reaction was diluted with ether (80 mL) and the
fluffy yellow precipitate collected by vacuum filtration. The precipitate was washed
with ether (50 mL) and became an oil on the fritted filter. Ethanol was used to wash
the product through the filter into a round bottom flask (50 mL). The flask was fitted
with a stir bar and DOWEX-66 (5.5 g) was added. The reaction was stirred for 2 hours.
The reaction was filtered and the filtrate concentrated to afford a yellow foam. The
product was purified by silica gel column chromatography (5-10% 2M ammonia in methanol,
95-90% dichloromethane) to afford a yellow oil. The oil was taken up in methanol (5
mL) and stirred during the addition of 1M hydrogen chloride in ether (3 mL). After
stirring for 2 hours the reaction was concentrated on the rotary evaporator. The resulting
yellow foam was dried further on the high vacuum line. Yield: 347 mg of yellow foam,
compound
56, 1H NMR (DMSO) δ 11.44 (br s, 1H), 11.26 (s, 1H), 10.62 (bs, 1H), 9.66 (bs, 1H), 8.61
(bs, 1H), 8.18-8.17 (d, 2H, J = 4.2 Hz), 7.65 (s, 1H), 7.54 - 7.51 (d, J = 8.7 Hz,
1H), 7.41 - 7.36 (q, 2H, J = 4.5 Hz), 7.13 - 7.09 (dd, J = 1.2, 8.7 Hz, 1H), 3.10
- 3.04 (t, J = 7.5, 2H), 2.79 - 2.74 (t, J = 7.5 Hz, 2H), 2.72 (s, 6H), 2.05 (m, 2H).
ESI-MS m/z (%): 327 (M
+, 100).
Example 15. Preparation of N-((3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)methyl)thiophene-2-carboximidamide (59).
[0226]
3-(2-(Dimethylamino)ethyl)-1H-indole-5-carbonitrile (57):
[0227] [2-(5-Bromo-1H-indol-3-yl)-ethyl]-dimethylamine
(16) (500.0 mg, 1.872 mmol) (
U.S. Patent No. 5,998,438) was placed in an argon purged oven dried flask fitted with a stirbar. Zinc cyanide
(395.0 mg, 3.368mmol, 1.8 equivalents); Zinc powder (14.7 mg. 0.225 mmol, 0.12 equivalents)
and tris(dibenzylideneacetone)dipalladium(0) (42.9 mg, 0.0468mmol), 0.025 equivalents)
were added sequentially followed by anhydrous
N,N-dimethylformamide (15 mL). A solution of tri-
t-butylphosphine in hexanes (10 wt%, 189.0 mg, 280 µl, 0.05 equivalents) was added
and the mixture was stirred for 15 minutes at room temperature and then heated in
an oil bath at 60 °C for 30 minutes. After cooling to room temperature the mixtures
was transferred into a separatory funnel and diluted with distilled water (15 mL).
The aqueous phase was extracted with ethyl acetate (3 x 30 mL). The combined organic
extracts were dried over magnesium sulfate, filtered, and concentrated. The residue
was purified via silica gel column chromatography (10% 2M NH
3 in methanol/ 90% dichloromethane) to provide 3-(2-(dimethylamino)ethyl)-1H-indole-5-carbonitrile
(57) as a yellow residue (150 mg, 37.6% yield).
1H NMR (DMSO) δ: 2.21 (s, 6H), 2.54 (m, 2 H), 2.84 (t, 2H), 7.36-7.41 (m, 2H), 7.49
(d, 1H), 8.07 (s, 1H), 11.38 (br s, 1H).
2-(5-(Aminomethyl)-1H-indol-3-yl)-N,N-dimethylethanamine (58):
[0228] Lithium aluminium hydride (40.0 mg, 1.055 mmol, 1.5 equivalents) was placed in an
argon purged oven dried flask fitted with a stirbar and condenser. Anhydrous diethylether
(5 mL) was added and stirring begun. 3-(2-Dimethylamino-ethyl)-1H-indole-5-carbonitrile
(57) (150.0 mg, 0.703 mmol, 1.0 equivalent) was dissolved in a separate dry flask in a
mixture of anhydrous diethylether (5 mL) and anhydrous tetrahydrofuran (5 mL) and
this solution added dropwise to the solution of lithium aluminium hydride and the
resulting mixture heated to reflux. After 30 minutes the reaction was cooled to room
temperature and quenched with distilled water (50 µL), aqueous 3N sodium hydroxide
solution (75 µL) and distilled water (150 µL) sequentially. The solution was filtered
and concentrated. The residue was purified via silica gel column chromatography (10-15-20%
2M NH
3 in methanol/90-85-80% dichloromethane) to provide 2-(5-(aminomethyl)-1H-indol-3-yl)-
N,N-dimethylethanamine
(58) as a pale yellow residue (73 mg, 47.8% yield).
1H NMR (DMSO) δ: 2.21 (s, 6H), 2.53 (m, 2 H), 2.78 (t, 2H), 3.79 (s, 2H), 7.02-7.05
(d, 1H), 7.09 (s, 1H), 7.24 (d, 1H), 7.44 (s, 1H), 10.66 (br s, 1H). MS: 218 (M+1),
201 (M+1-NH
3).
[0229] N-((3-(2-(Dimethylamino)ethyl)-1H-indol-5-yl)methyl)thiophene-2-carboximidamide (59): [2-(5-Aminomethyl-1H-indol-3-yl)-ethyl]-dimethylamine
(58) (70 mg, 0.322 mmol) and thiophene-2-carboximidothioic acid methyl ester hydroiodide
(160.7 mg, 0.564 mmol, 1.75 equivalents) were dissolved in anhydrous ethanol (5 mL)
in a small, argon purged flask. The reaction was stirred under argon for 20 hours
at ambient temperature at which time the solvent was removed. The crude residue was
dissolved in water (10 mL) and transferred to a separatory funnel, where it was made
basic (pH 9-10) through the addition of aqueous 1N sodium hydroxide solution. The
mixture was extracted with ethyl acetate (3 x 20 mL). The combined organic extracts
were washed with distilled water, brine, dried over magnesium sulfate, filtered and
concentrated to yield crude freebase. The residue was purified via silica gel column
chromatography (10-25% 2M NH
3 in methanol/ 90-75% dichloromethane) to provide the freebase as a colorless/white
residue (36 mg, 34.3% yield). The freebase was dissolved in methanol (5 mL) and 1M
HCl in diethylether (3 equivalents) was added. The solvent was removed and the oil
dried under high vacuum to give
N-((3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)methyl)thiophene-2-carboximidamide
(59) as the dihydrochloride salt.
1H NMR (free base, DMSO-d6) δ: 2.21 (s, 6H), 2.53 (m, 2 H), 2.79 (t, 2H), 4.39 (s,
2H), 7.06-7.10 (m, 3H), 7.26 (d, 1H), 7.51 (s, 1H), 7.52 (m, 1H), 7.60 (d, 1H), 10.65
(br s, 1H). MS: 327 (M+1).
Example 16. N-(3-(1-ethylpiperin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (62).
[0230]
3-(1-Ethyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (60):
[0231] A solution of 5-nitroindole
(38) (0.5 g, 3.083 mmol) in dry ethanol (15 mL) was treated with pyrrolidine (0.65 mL,
9.250 mmol),
N-ethyl-4-piperidone (0.8 mL, 6.167 mmol) at room temperature and the resulting solution
was refluxed for 3 days. The reaction was brought to room temperature and solvent
was evaporated. The crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95), and washed with ether (3 x 10 mL) to obtain compound
60 (0.35 g, 42%) as a solid. mp 188-190 °C;
1H NMR (DMSO-
d6) δ: 1.07 (t, 3H,
J = 7.2 Hz), 2.41-2.50 (m, 4H), 2.63 (t, 2H,
J = 5.1 Hz), 3.10-3.15 (m, 2H), 6.18 (s, 1H), 7.55 (d, 1H,
J = 9.0 Hz), 7.65 (s, 1H), 8.01 (dd, 1H,
J = 2.1, 9.0 Hz), 8.69 (d, 1H,
J = 2.1 Hz), 11.86 (s, 1H); ESI-MS m/z (%): 272 (M
+, 100).
N-(3-(1-ethylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (61):
[0232] A solution of 3-(1-ethyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole
(60) (0.1 g, 0.368 mmol) in dry ethanol (5 mL) was treated with 10% Pd-C (0.02 g), purged
with hydrogen gas and stirred for 4 h under hydrogen atm. (balloon pressure). The
solid was filtered off using celite bed and washed with dry ethanol (2 × 5 mL). The
combined ethanol layer was treated with thiophene-2-carboximidothioic acid methyl
ester hydroiodide (0.21 g, 0.737 mmol) and stirred for 24 h at room temperature. The
solvent was evaporated and product was precipitated with ether (100 mL). The solid
was filtered and dissolved into sat NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain
N-(3-(1-ethylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(61) (0.085 g, 66%) as a solid. mp 150-152 °C;
1H NMR (DMSO-
d6) δ 1.01 (t, 3H,
J = 6.9 Hz), 1.59-1.75 (m, 2H), 1.90-2.05 (m, 4H), 2.35 (q, 2H), 2.65-2.73 (m, 1H),
2.94-2.97 (m, 2H), 6.23 (brs, 1H), 6.62 (dd, 1H,
J = 1.2, 8.4 Hz), 6.97 (s, 1H), 7.02 (d, 1H,
J = 2.1 Hz), 7.09 (t, 1H,
J = 4.2 Hz), 7.26 (d, 1H,
J = 8.4 Hz), 7.58 (d, 1H,
J = 5.4 Hz), 7.70 (d, 1H,
J = 3.6 Hz), 10.59 (s, 1H); ESI-MS m/z (%): 353 (M
+, 100).
[0233] Dihydrochloride salt of N-(3-(1-ethylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(62): A solution of
N-(3-(1-ethylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(61) (0.07 g, 0.198 mmol) in ethanol (2 mL) was treated with 1 N HCl in ether (0.59 mL,
0.595 mmol) at room temperature. The solvent was evaporated after stirring for 15
min. and the crude was recrystallised from ethanol/ether to obtain compound
62 (0.067 g, 80%) as a solid. mp 254-256 °C.
Example 17. N-(3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamothioyl)benzamide
(64).
[0234]
3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (39):
[0235] Experimental details were discussed in Example 11.
[0236] N-(3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamothioyl) benzamide
(63). A solution of compound 3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole
(39) (1.0 g, 3.886 mmol) in dry methanol (20 mL) was treated with Raney-Ni (0.3 g), followed
by hydrazine hydrate (1.21 mL, 38.866 mmol) at room temperature and the resulting
solution was stirred at 65 °C for 2 h. The reaction was brought to room temperature
and the mixture filtered through a celite bed to remove the solid. The celite bed
was washed with methanol (2 × 10 mL). The combined organic fraction was evaporated
and the crude material was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain the free amine 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-amine
(0.78 g, 88%) as a solid. A solution of the amine (0.78 g, 3.431 mmol) in acetone
(20 mL) was treated with benzoylisothiocyanate (0.53 mL, 3.946 mmol) at room temperature
and the resulting mixture was stirred for overnight. The solvent was evaporated and
the crude product was purified by column chromatography (2M ammonia in methanol: CH
2Cl
2, 5:95) to obtain compound
63 (1.23 g, 92%) as a solid. mp 182-184 °C;
1H NMR (DMSO-
d6) δ 2.28 (s, 3H), 2.50-2.58 (m, 4H), 3.00-3.10 (m, 2H), 6.09 (s, 1H), 7.26 (d, 1H,
J = 7.8 Hz), 7.40 (d, 1H,
J = 8.7 Hz), 7.44 (d, 1H,
J = 2.1 Hz), 7.54 (t, 2H,
J = 7.5 Hz), 7.66 (t, 1H,
J = 7.2 Hz), 7.99 (d, 2H,
J = 7.5 Hz), 8.15 (s, 1H), 11.24 (s, 1H), 11.48 (s, 1H), 12.58 (s, 1H); ESI-MS m/z
(%):: 391 (M
+, 76), 289 (74), 348 (100).
Hydrochloride salt of
N-(3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamothioyl)benzamide
(64): A solution of compound
63 (0.08 g, 0.204 mmol) in methanol (5 mL) was treated with 1 N HCl in ether (0.6 mL,
0.614 mmol) at room temperature. The solvent was evaporated under vacuum after stirring
for 15 min. and the crude was recrystallised from ethanol/ether to obtain compound
64 (0.075 g, 80%) as a solid. mp 197-199 °C.
Example 18. Preparation of Ethyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(67):
[0237]
N-(3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamothioyl) benzamide
(63): Synthesis was described in Example 17.
[0238] 1-(3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)thiourea (65): A solution of compound
63 (1.12 g, 2.868 mmol) in THF (20 mL) was treated with 2 N NaOH (3.1 mL, 6.309 mmol)
at room temperature and the resulting solution was refluxed for 5 h. The reaction
was brought to room temperature, solvent was evaporated. The crude was diluted with
water (20 mL) and ethyl acetate (20 mL). The precipitated solid was filtered, washed
with water (10 mL), EtOAc (10 mL) and ether (2 × 10 mL) and dried under vacuum to
obtain compound
65 (0.65 g, 79%). mp 209-211 °C;
1H NMR (DMSO-
d6) δ 2.27 (s, 3H), 2.50-2.56 (m, 4H), 3.00-3.08 (m, 2H), 6.05 (s, 1H), 6.98 (d, 1H,
J = 8.4 Hz), 7.32-7.40 (m, 3H), 7.67 (s, 1H), 9.51 (s, 1H), 11.15 (s, 1H); ESI-MS m/z
(%):: 287 (M+, 71), 249 (46), 244 (100).
[0239] Ethyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(66): A solution of compound
65 (0.2 g, 0.698 mmol) in acetone (10 mL) was treated with iodoethane (0.33 mL, 4.189
mmol) at room temperature and the resulting solution was reflexed for 4 h. The reaction
was brought to room temperature, and solvent was evaporated. The crude was diluted
with sat. NaHCO
3 solution (20 mL) and compound was extracted into CH
2Cl
2 (3 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4) Evaporation of solvent and purification of crude by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
66 (0.055 g, 25%) as a solid. mp 77-79 °C;
1H NMR (DMSO-
d6) δ 1.20-1.30 (m, 3H), 2.28 (s, 3H), 2.50-2.57 (m, 4H), 2.90-2.96 (m, 2H), 3.02-3.06
(m, 2H), 5.98-6.04 (m, 2H), 6.60-6.63 (m, 1H), 7.17-7.35 (m, 4H), 10.90 (s, 1H); ESI-MS
m/z (%):: 315 (M+, 66), 311 (78), 249 (100).
[0240] Dihydrochloride salt of ethyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(67): A solution of compound
66 (0.05 g, 0.159 mmol) in methanol (5 mL) was treated with 1 N HCl in ether (0.47 mL,
0.477 mmol) at room temperature. The solvent was evaporated under vacuum after stirring
for 15 min. and the crude was recrystallised from ethanol/Ether to obtain compound
67 (0.04 g, 66%) as a solid. mp 190-192 °C.
Example 19. N-(3-(1-benzoylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (70)
[0241]
(4-(5-Nitro-1H-indol-3-yl)-5,6-dihydropyridin-1(2H)-yl)(phenyl)methanone (68):
[0242] A solution of 5-nitroindole
(38) (0.5 g, 3.083 mmol) in dry ethanol (15 mL) was treated with pyrrolidine (0.77 mL,
9.250 mmol), 1-benzoyl-4-piperidone (1.0 g, 4.933 mmol) at room temperature and resulting
solution was refluxed for 3 days. The reaction cooled to room temperature and the
solid was filtered off. The product was washed with cold ethanol (2 × 10 mL) and dried
under vacuum to obtain compound
68 (1.05 g, 98%) as a solid. mp 280-282 °C;
1H NMR (DMSO-
d6) δ 2.55-2.61 (m, 2H), 3.54-3.58 (m, 1H), 3.86-3.90 (m, 1H), 4.15-4.34 (m, 2H), 6.14-6.30
(m, 1H), 7.39-7.55 (m, 5H), 7.67 (d, 1H,
J = 9.6 Hz), 7.72 (s, 1H), 8.03 (d, 1H,
J = 8.1 Hz), 8.70-8.78 (m, 1H), 11.94 (s, 1H); ESI-MS m/z (%): 348 (M
+, 100), 276 (83), 244 (40).
[0243] Dihydrochloride salt of N-(3-(1-Benzoylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(70): A solution of compound 1 (0.2 g, 0.575 mmol) in dry ethanol (5 mL) was treated with
Pd-C (0.02 g), purged with hydrogen gas and stirred for overnight (14 h) under hydrogen
atm. (balloon pressure). The reaction mixture was filtered through celite bed and
washed with dry ethanol (2 × 5 mL). The combined ethanol layer was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.32 g, 1.157 mmol) and the resulting mixture was stirred
for 24 h at room temperature. The solvent was evaporated and product was precipitated
with ether (50 mL). The solid was partitioned between sat. NaHCO
3 solution: CH
2Cl
2 (40 mL, 1:1). The organic layer was separated and aqueous layer was extracted with
CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (10 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was product was purified by column chromatography
(2M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
69 (0.07 g, 28%) as a free base. Solid, mp 135-137 °C;
1H NMR (DMSO-
d6) δ 1.57-1.65 (m, 2H), 1.89-2.06 (m, 2H), 2.92-3.08 (m, 2H), 3.18-3.25 (m, 1H), 3.64-3.69
(m, 1H), 4.58-4.64 (m, 1H), 6.22 (s, 1H), 6.63 (d, 1H,
J = 8.7 Hz), 7.01-7.10 (m, 3H), 7.27 (d, 1H,
J = 8.4 Hz), 7.40-7.45 (m, 6H), 7.58 (d, 1H,
J = 4.8 Hz), 7.70 (d, 1H,
J = 3.6 Hz), 10.65 (s, 1H); ESI-MS m/z (%): 429 (M
+, 100), 412 (46). A solution of compound
69 (0.06 g, 0.140 mmol) in methanol (3 mL) was treated with 1 N HCl in ether (0.42 mL,
0.420 mmol) and stirred for 30 min at room temperature. The solvent was evaporated
and crude was recrystallized from ethanol/ether to obtain compound
70 (0.053 g, 76%) as a solid. mp 180-183 °C.
Example 20. N-(3-(Pyridin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (73)
[0244]
3-(1-Benzyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (71):
[0245] A solution of 5-nitroindole
(38) (1.0 g, 6.167 mmol) in dry ethanol (20 mL) was treated with pyrrolidine (1.54 mL,
18.501 mmol),
N-benzyl-4-piperidone (2.2 mL, 12.3 mmol) at room temperature and the resulting solution
was refluxed for 4 days. The reaction was brought to room temperature and solvent
was evaporated. The crude product was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
71 (0.925 g, 45%) as a solid. mp 168-170 °C;
1H NMR (DMSO-
d6) δ 2.51-2.55 (m, 2H), 2.66 (t, 2H,
J = 5.4 Hz), 3.12-3.18 (m, 2H), 3.60 (s, 2H), 6.17 (s, 1H), 7.23-7.38 (m, 5H), 7.55
(d, 1H,
J = 9.0 Hz), 7.65 (s, 1H), 8.01 (dd, 1H,
J = 2.1, 8.7 Hz), 8.68 (d, 1H,
J = 2.1 Hz), 11.87 (s, 1H); ESI-MS m/z (%): 334 (M
+, 100).
[0246] Dihydrochloride salt of N-(3-(pyridin-4-yl)-1H-indol-5-yl) thiophene-2-carboximidamide
(73): A solution of compound
71 (0.3 g, 0.899 mmol) in dry methanol (5 mL) was treated with Pd-C (0.03 g), HCO
2NH
4 (0.28 g, 4.499 mmol) at room temperature and the resulting solution was refluxed
for 24 h. The reaction was brought to room temperature, filtered through celite bed
and washed with methanol (2 × 15 mL). The combined methanol layer was evaporated and
crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain the amine intermediate.
A solution of the amine in dry ethanol (10 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.51 g, 1.799 mmol) and the resulting mixture was stirred
for 24 h at room temperature. The solvent was evaporated and product was precipitated
with ether (50 mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (40 mL, 1:1). The organic layer was separated and aqueous layer was extracted with
CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound 72 (0.04 g, 14%) as a solid. mp 112-115 °C;
1HNMR (DMSO-
d6) δ 6.39 (brs, 1H), 6.76 (d, 1H,
J = 8.4 Hz), 7.10 (dd, 1H,
J= 3.6, 4.9 Hz), 7.41-7.44 (m, 2H), 7.61 (d, 1H,
J= 4.8 Hz), 7.68 (d, 2H,
J = 6.3 Hz), 7.74 (d, 1H,
J = 2.7 Hz), 7.96 (d, 1H,
J = 2.7 Hz), 8.49 (d, 2H,
J = 6.0 Hz), 11.53 (s, 1H); ESI-MS m/z (%): 319 (M
+, 100). A solution of free base of compound
72 (0.035 g, 0.109 mmol) in methanol (3 mL) was treated with 1 N HCl in ether (0.32
mL, 0.329 mmol) and stirred for 30 min. at room temperature. The solvent was evaporated
and crude was recrystallized from ethanol/ether to obtain compound
73 (0.031 g, 72%) as a dihydrochloride salt. Solid, mp 183-185 °C.
Example 21: Methyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(75)
[0247]
1-(3-(1-Methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)thiourea (64):
[0248] Please see Example 17 for experimental details.
[0249] Methyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(74): A solution of compound
64 (0.2 g, 0.698 mmol) in acetone (10 mL) was treated with iodomethane (0.26 mL, 4.189
mmol) at room temperature and the resulting solution was refluxed for over night (14
h). The reaction was brought to room temperature and solvent was evaporated. The crude
was diluted with sat NaHCO
3 solution (10 mL) and compound was extracted into CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (10 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
74 (0.04 g, 19%) as a solid. mp 260-162 °C;
1HNMR (DMSO-
d6) δ 2.29 (s, 3H), 2.33 (s, 3H), 2.50-2.59 (m, 4H), 3.06 (brs, 2H), 6.01 (s, 1H), 6.64
(brs, 1H), 7.22-7.30 (m, 3H), 10.91 (s, 1H); ESI-MS m/z (%): 301 (M
+, 36), 285 (55), 258 (66), 242 (100).
[0250] Di hydrochloride salt of Methyl 3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-ylcarbamimidothioate
(75): A solution of compound
74 (0.035 g, 0.116 mmol) in methanol (3 mL) was treated with 1 N HCl in ether (0.34
mL, 0.349 mmol) at room temperature. The solvent was evaporated under vacuum after
stirring for 15 min and dried to obtain compound
75 (0.03 g, 70%) as a semi-solid.
Example 22. N-(3-(1-(imino(thiophen-2-yl)methyl)piperidin-4-yl)-1H-indol-5-yl)thiophene-2-carbozimidamide
(77)
[0251]
[0252] 3-(1-Benzyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (71): Please see Example 20 for experimental details.
[0253] N-(3-(1-(imino(thiophen-2-yl)methyl)piperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(76): A solution of compound
71 (0.17 g, 0.509 mmol) in dry ethanol (5 mL) was treated with Pd-C (0.02 g), purged
with hydrogen gas and stirred for overnight (14 h) under hydrogen atm. (balloon pressure).
The reaction mixture was filtered through celite bed and washed with dry ethanol (2
× 5 mL). The combined ethanol layer was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.32 g, 1.019 mmol) and the resulting mixture was stirred
for 24 h at room temperature. The solvent was evaporated and product was precipitated
with ether (50 mL). The solid was dissolved into a mixture of sat. NaHCO
3 sol. and CH
2Cl
2 (40 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
7 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (10 mL) and dried (Na
2SO
4). The solvent was evaporated and crude product was purified by column chromatography
(2M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
77 (0.06 g, 27%) as a solid. mp 115-117 °C;
1H NMR (DMSO-
d6) δ 1.66-1.77 (m, 2H), 1.99-2.03 (m, 2H), 3.04-3.16 (m, 3H), 3.97-4.01 (m, 2H), 6.23
(brs, 1H), 6.64 (dd, 1H,
J = 1.2, 8.4 Hz), 7.03 (s, 1H), 7.07-7.10 (m, 2H), 7.17 (t, 1H,
J = 3.9 Hz), 7.28 (d, 1H,
J = 8.4 Hz), 7.43 (d, 1H,
J = 3.9 Hz), 7.58 (d, 1H,
J = 4.5 Hz), 7.71 (d, 1H,
J = 3.6 Hz), 7.78 (d, 1H,
J = 4.5 Hz), 10.65 (s, 1H); ESI-MS m/z (%): 434 (M+, 47), 325 (100), 242 (34).
[0254] Di hydrochloride salt of N-(3-(1-(imino(thiophen-2-yl)methyl)piperidin4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(77): A solution of compound
76 (0.055 g, 0.115 mmol) in methanol (3 mL) was treated with 1 N HCl in ether (0.34
mL, 0.345 mmol) and stirred for 30 min at room temeprature. The solvent was evaporated
and crude was recrystallized from ethanol/ether to obtain compound
77 (0.051 g, 80%) as a solid. mp 123-125 °C.
Example 23. N-(3-(4-(methylamino)cyclohexyl)-1H-indol-5-yl)thiophene-2-carboximidamide (84):
[0255]
[0256] 5-Nitro-3-(1,4-dioxaspiro[4.5]dec-7-en-8-yl)-1H-indole (78): A solution of 5-nitroindole
(38) (0.2 g, 1.233 mmol) in dry methanol (5 mL) was treated with KOH (0.56 g) at room
temperature. After stirring for 10 min., 1, 4-cyclohexanedione monoethylene ketal
(0.48 g, 3.083 mmol) was added and the resulting solution was refluxed for 36 h. The
reaction was brought to room temperature and solvent was evaporated. The crude product
was diluted with water (25 mL) and product was extracted into ethyl acetate (2 × 25
mL). The combined ethyl acetate layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude material was purified by flash-column chromatography
(ethyla acetate) to obtain compound
78 (0.25 g, 68%) as a solid. mp 175-177 °C;
1H NMR (CDCl
3) δ 1.91 (t, 2H,
J = 6.6 Hz), 2.49 (brs, 2H), 2.49-2.66 (m, 2H), 3.96-4.00 (m, 4H), 6.12 (t, 1H,
J = 3.9 Hz), 7.22 (d, 1H,
J = 2.4 Hz), 7.32 (d, 1H,
J = 8.7 Hz), 8.05 (dd, 1H,
J = 2.1, 9.0 Hz), 8.36 (brs, 1H), 8.78 (d, 1H,
J = 2.1 Hz); ESI-MS m/z (%): 301 (M
+, 100).
[0257] 4-(5-Nitro-1H-indol-3-yl)cyclohex-3-enone (79): A solution of compound
78 (0.1 g, 0.332 mmol) in acetone (5 mL) was treated with 10 % aq. HCl (5 mL) at room
temperature and stirred for 6h. Acetone was evaporated and crude was basified using
NH
4OH solution (20 mL). The product was extracted into CH
2Cl
2 (2 × 20 mL), washed with brine (10 mL) and dried (Na
2SO
4). The CH
2Cl
2 layer was evaporated to obtain compound
79 (0.075 g, 88%) as a solid. mp 210-212 °C;
1H NMR (DMSO-
d6) δ 2.59 (t, 2H,
J = 6.9 Hz), 2.90 (t, 2H,
J = 6.6 Hz), 3.11-3.12 (m, 2H), 6.24 (t, 1H,
J= 3.6 Hz), 7.57 (d, 1H,
J= 9.0 Hz), 7.76 (d, 1H,
J= 2.1 Hz), 8.03 (dd, 1H,
J = 2.1, 9.0 Hz), 8.71 (d, 1H,
J = 2.1 Hz), 11.95 (s, 1H); ESI-MS m/z (%): 257 (M
+, 100).
[0258] N-Methyl-4-(5-nitro-1H-indol-3-yl)cyclohex-3-enamine (80): A solution of compound
79 (0.07 g, 0.273 mmol) in 1, 2-dichloroethane (3 mL) was treated with AcOH (0.015 mL,
0.273 mmol), methylamine hydrochloride (0.018 g, 0.273 mmol), NaBH(OAC)
3 (0.086 g, 0.409 mmol) at room temperature and stirred for over night (14 h). The
reaction was basified with 2 N NaOH (25 mL) and product was extracted into ethyl acetate
(2 × 20 mL). The combined ethyl acetate layer was washed with brine (15 mL) and dried
(Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
80 (0.074 g, quantitative) as a solid. mp 208-210 °C;
1H NMR (DMSO-
d6) δ 1.44-1.53 (m, 1H), 1.97-2.01 (m, 2H), 2.35 (s, 3H), 2.40-2.57 (m, 3H), 2.60-2.70
(m, 1H), 6.13 (brs, 1H), 7.54 (d,1H,
J = 9.0 Hz), 7.63 (s, 1H), 8.00 (d, 1H,
J = 7.5 Hz), 8.67 (s, 1H), 11,85 (brs, 1H); ESI-MS m/z (%): 272 (M
+, 100).
tert-Butyl methyl(4-(5-nitro-1H-indol-3-yl)cyclohex-3-enyl)carbamate (81): A solution of compound
80 (0.1 g, 0.368 mmol) in dry 1, 4- dioxane (3 mL) was treated with Et
3N (0.1 mL, 0.737 mmol) followed by (Boc)
2O (0.084 g, 0.387 mmol) at room temperature and the resulting solution was stirred
for over night (16 h). Solvent was evaporated and crude was purified by column chromatography
(EtOAc: Hexanes, 1:1) to obtain compound
81 (0.135 g, quantitative) as a solid. mp 224-226 °C;
1H NMR (DMSO-
d6) δ 1.42 (s, 9H), 1.81-1.87 (m, 2H), 2.29-2.45 (m, 2H), 2.60-2.70 (m, 2H), 2.74 (s,
3H), 4.10-4.16 (m, 1H), 6.17 (brs, 1H), 7.55 (d, 1H,
J = 9.0 Hz), 7.66 (s, 1H), 8.01 (dd, 1H,
J = 2.4, 9.0 Hz), 8.68 (d, 1H,
J = 2.1 Hz), 11.87 (s, 1H); ESI-MS m/z (%): 394 (M.Na
+, 100), 316 (44), 272 (82).
tert-Butyl 4-(5-amino-1H-indol-3-yl)cyclohex-3-enyl(methyl)carbamate (82):
[0259] A solution of compound
81 (0.5 g, 1.364 mmol) in 2 M NH
3 in methanol (20 mL) was treated with Pd-C (0.05 g) and flushed with hydrogen gas.
The reaction was stirred at room temperature for over night (16 h) under hydrogen
atm. (balloon pressure). The solution was filtered using celite bed and washed with
CH
2Cl
2: methanol (1:1, 3 × 20 mL). The solvent was evaporated and crude was purified by
column chromatography (EtOAc: Hexanes, 1:1) to obtain compound
82 (0.46 g, quantitative) as a solid in 1:2 ratio of diastereomers.
1H NMR (DMSO-
d6) δ 1.38, 1.41 (2s, 9H), 1.46-1.84 (m, 6H), 2.02-2.17 (m, 2H), 2.53-2.57 (m, 1H),
2.60-2.72 (2s, 3H), 3.82-3.85 (m, 1H), 4.41 (brs, 2H), 6.42-6.50 (m, 1H), 6.66-6.68
(m, 1H), 6.85-6.87, 6.99-7.06 (2m, 2H), 10.23, 10.28 (2s, 1H); ESI-MS m/z (%): 366
(M.Na
+, 8), 344 (MH
+, 10), 288 (100).
[0260] tert-Butyl methyl(4-(5-(thiophene-2-carboximidamido)-1H-indol-3-yl)cyclohexyl)carbamate
(83): A solution of compound
82 (0.44 g, 1.281 mmol) in dry ethanol (20 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.73 g, 2.562 mmol) at room temperature and stirred
for 24 h. The solvent was evaporated and product was precipitated with ether (100
mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 25 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
83 (0.425 g, 73%) as a foam in 1:2 ration of diastereomers.
1H NMR (DMSO-
d6) δ 1.38-1.56 (m, 11H), 1.64-1.82 (m, 4H), 2.06-2.18 (m, 2H), 2.62-2.70 (m, 4H), 3.80-3.90
(m, 1H), 6.27 (brs, 1H), 6.62-6.66 (m, 1H), 6.95-7.11 (m, 3H), 7.22-7.29 (m, 1H),
7.59 (d, 1H,
J = 5.1 Hz), 7.71 (d, 1H,
J = 3.6 Hz), 10.59, 10.63 (2s, 1H); ESI-MS m/z (%): 453 (MH
+, 100).
[0261] Di hydrochloride salt of N-(3-(4-(methylamino)cyclohexyl)-1H-indol-5-yl)thiophene-2-carboximidamide
(84): Compound
83 (0.2 g, 0.441 mmol) was treated with 1 N HCl solution at room temperature and the
resulting solution was refluxed for 2 h. The reaction was brought to room temperature,
filtered and washed with water (5 mL). The solvent was evaporated and crude was recrystallised
from ethanol/ether to obtain compound
84 (0.175 g, 94%) as a solid in 1:2 ratio of diastereomers.
1H NMR (DMSO-
d6) δ 1.52-1.56 (m, 2H), 1.81-2.16 (m, 6H), 2.50 (s, 3H), 2.75-2.80 (m, 1H), 3.00-3.05
(m, 1H), 7.08 (d, 1H,
J = 8.1 Hz), 7.24-7.40 (m, 2H), 7.50 (d, 1H,
J = 8.7 Hz), 7.70-7.72 (m, 1H), 8.15-8.19 (m, 2H), 8.58 (brs, 1H), 9.19 (brs, 2H),
9.65 (brs, 1H), 11.21, 11.26 (2s, 1H), 11.43 (s, 1H); ESI-MS m/z (%): 353 (MH
+ for free base, 100) 322 (85); ESI-HRMS calculated for C
20H
25N
4S (MH
+ for free base), Calculated: 353.1808; Observed: 353.1794.
Example 24. N-(3-(piperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (88)
[0262]
[0263] tert-Butyl 4-(5-nitro-1H-indol-3-yl)-5,6-dihydropyridine-1(2H)-carboxylate (
85): A solution of 5-nitroindole (
38) (2.0 g, 12.334 mmol) in dry ethanol, (20 mL) was treated with pyrrolidine (3.08
mL, 37.002 mmol) followed by
N-Boc-4-piperidone (4.91 g, 24.668 mmol) at room temperature and the resulting solution
was refluxed for 3 days. The reaction was brought to room temperature, the solvent
was evaporated and the crude product was purified by column chromatography (ethyl
acetate: hexanes, 1:3) to obtain compound
85 (4.2 g, quantitative) as a solid. mp 210-212 °C;
1H NMR (DMSO-
d6) δ 1.36-1.43 (m, 11H), 3.57 (t, 2H,
J = 5.7 Hz), 4.08 (s, 2H), 6.20 (s, 1H), 7.56 (d, 1H,
J = 9.0 Hz), 7.71 (s, 1H), 8.02 (dd, 1H,
J = 2.1, 9.0 Hz), 8.71 (d, 1H,
J = 2.1, Hz), 11.93 (s, 1H); ESI-MS m/z (%): 366 (M.Na
+, 100), 288 (52).
[0264] tert-Butyl 4-(5-amino-1H-indol-3-yl)piperidine-1-carboxylate (86): A solution of compound
85 (0.5 g, 1.456 mmol) in 2 M NH
3 in methanol (15 mL) was treated with Pd-C (0.05 g) and purged with hydrogen gas.
The reaction was stirred under hydrogen atm. for overnight. The solution was filtered
through a celite bed and washed with methanol: CH
2Cl
2 (1:1, 2 × 20 mL). The combined organic layer was evaporated to obtain compound
86 (0.46 g, quantitative) as a solid. mp 205-207 °C;
1H NMR (DMSO-
d6) δ 1.41-1.53 (m, 11H), 1.87-1.91 (m, 2H), 2.73-2.85 (m, 3H), 4.03-4.07 (m, 2H), 4.43
(s, 2H), 6.45 (dd, 1H,
J = 1.8, 8.4 Hz), 6.69 (d, 1H,
J =1.5 Hz), 6.90 (d, 1H,
J = 2.4 Hz), 7.01 (d, 1H,
J = 8.4 Hz), 10.28 (s, 1H); ESI-MS m/z (%): 338 (M.Na
+, 23), 316 (MH
+,11), 216 (100).
[0265] tert-Butyl 4-(5-(thiophene-2-carboximidamido)-1H-indol-3-yl)piperidine-1-carboxylate (87): A solution of compound
86 (0.45 g, 1.426 mmol) in dry ethanol (25 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.81 g, 2.853 mmol) at room temperature and resulting
solution was stirred for 24 h. The solvent was evaporated, crude was diluted with
sat. NaHCO
3 solution (25 mL) and CH
2Cl
2 (50 mL). The organic layer was separated and aqueous layer was extracted into CH
2Cl
2 (2 × 25 mL). The combined organic layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and the crude product was purified by column chromatography
on silica gel (2 M NH
3 in methanol: CH
2Cl
2, 3:97) to obtain compound
87 (0.6 g, quantitative) as a foam.
1H NMR (DMSO-
d6) δ 1.40-1.56 (m, 11H), 1,90-1.94 (m, 2H), 2.86-2.94 (m, 3H), 4.02-4.06 (m, 2H), 6.26
(s, 1H), 6.64 (dd, 1H,
J = 1.2, 8.4 Hz), 6.99 (s, 1H), 7.05 (d, 1H,
J = 1.8 Hz), 7.09 (dd, 1H,
J = 3.6, 4.9 Hz), 7.27 (d, 1H,
J = 8.4 Hz), 7.59 (d, 1H,
J = 5.1 Hz), 7.71 (d, 1H,
J = 3.3 Hz), 10.63 (s, 1H); ESI-MS m/z (%): 425 (MH
+, 100).
[0266] Dihydrochloride salt of N-(3-(piperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (88): A solution of compound
87 (0.3 g, 0.706 mmol) was treated with 1 N HCl solution (20 mL) and refluxed for 2
h. The reaction was brought to room temperature, solid was filtered off and washed
with water (5 mL). The water layer was evaporated and crude was recrystallised from
ethanol / ether to obtain compound
88 (0.29 g, 72%) as a solid. Decomposed at 230°C.
1H NMR (DMSO-
d6) δ 1.90-2.10 (m, 4H), 3.00-3.13 (m, 3H), 3.31-3.35 (m, 2H), 7.11 (d, 1H,
J = 8.7 Hz), 7.28 (d, 1H,
J =
1.8 Hz), 7.39 (t, 1H,
J = 4.5 Hz), 7.53 (d, 1H,
J = 8.7 Hz), 7.77 (s, 1H), 8.16-8.20 (m, 2H), 8.58 (s, 1H), 9.18 (brs, 2H), 9.68 (s,
1H), 11.29 (s, 1H), 11.49 (s, 1H); ESI-MS m/z (%): 325 (MH
+, free base, 100), 242 (34), 163 (70); HRMS Calculated for C
18H
21N
4S (MH
+); Calculated: 325.1494; Found: 325.1481.
Example 25. N-(3-(8-methyl-8-azabicyclo[3.2.1]oct-3-en-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(90):
[0267]
[0268] 3-(8-Methyl-8-azabicyclo[3.2.1]oct-3-en-3-yl)-5-nitro-1H-indole (89): A solution of 5-nitroindole (
38) (0.5 g, 3.083 mmol) in glacial acetic acid (10 mL) was treated with tropinone (0.85
g, 6.617 mmol), followed by 2 M H
3PO
4 in glacial acetic acid (5 mL) at 100 °C and the resulting solution was stirred at
same temperature for 24 h. The reaction was brought to room temperature, poured in
to ice-cold 10% NH
4OH solution (50 mL) and product was extracted into CH
2Cl
2 (2 × 25 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude material was purified by column chromatography
on silica gel (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
89 (0.27 g, 31%) as a solid. mp 234-236 °C;
1H NMR (DMSO-
d6) δ 1.51-1.60 (m, 1H), 1.79-1.86 (m, 1H), 1.95-2.14 (m, 4H), 2.32 (s, 3H), 2.76-2.83
(m, 1H), 3.43 (t, 1H,
J = 5.4 Hz), 6.31 (d, 1H,
J = 5.1 Hz), 7.54 (d, 1H,
J = 8.7 Hz), 7.61 (s, 1H), 8.01 (dd, 1H,
J = 2.1, 9.0 Hz), 8.68 (d, 1H,
J = 2.4 Hz), 11.86 (s, 1H); ESI-MS m/z (%): 284 (MH
+, 100).
[0269] N-(3-(8-Methyl-8-azabicyclo[3.2.1]oct-3-en-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(90): A solution of compound
89 (0.25 g, 0.882 mmol) in dry ethanol (10 mL) was treated with Pd-C (0.025 g) and purged
with hydrogen gas. The reaction was stirred under hydrogen atm. (balloon pressure)
for overnight (14 h). The solid was filtered off using celite bed and washed with
ethanol (2 × 5 mL). The combined ethanol layer was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.5 g, 1.764 mmol) at room temperature and stirred
for 24 h. Ethanol was evaporated and crude material was basified with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 25 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography on silica
gel (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
90 (0.14 g, 44%) as a solid. mp 93-95 °C;
1H NMR (DMSO-
d6) δ 1.60-1.65 (m, 1H), 1.84-1.90 (m, 1H), 2.02-2.26 (m, 4H), 2.41 (s, 3H), 2.83-2.89
(m, 1H), 3.46-3.55 (m, 1H), 6.20 (brs, 2H), 6.67 (d, 1H,
J = 7.8 Hz), 7.10 (s, 1H), 7.23-7.31 (m, 3H), 7.60-7.72 (m, 2H), 10.99 (s, 1H); ESI-MS
m/z (%): 363 (MH
+, 65), 182 (100), 119 (48); ESI-HRMS calculated for C
21H
23N4S (MH
+), Calculated: 363.1633; Observed: 363.1637.
Example 26. (R)-N-(3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)thiophene-2-carboximidamide (97):
[0270]
[0271] 5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indole (92) (
Macor et. al. J Org. Chem. 1994, 59(24), 7496): To a 250 mL argon purged round bottom flask containing a magnetic stirbar and a
solution of 5-aminoindole (
91) (15.00 g, 113 mmol) in anhydrous toluene (50 mL) was added acetonylacetone (25.4
mL, 216 mmol, 1.9 eq). The flask was fitted with a Dean-Stark trap with a 10 mL reservoir
filled with toluene. The uppermost portion of the flask and the condensing arm of
the trap were wrapped with foil and the reaction vessel placed into an oil bath preheated
to a temperature of 125°C. The dark brown solution was allowed to stir under a continuous
flow of argon at this temperature for 45 minutes, followed by draining of the trap
solvent reservoir. After a total of 4 hours, TLC (5% ethyl acetate, 95% hexanes) revealed
the reaction was complete. The reaction was cooled gradually to room temperature overnight.
The reaction was poured onto a plug of silica gel and the solvent pulled through by
vacuum filtration. The silica was washed with hexanes (200 mL). A white precipitate
started to form almost immediately in the filtrate. The silica was washed again with
a solution of 6% diethyl ether, 94% hexanes (800 mL). Crystals were collected from
both washes, and the filtrates combined. The plug was washed with ether (150 mL) and
the filtrate combined with the washes. The combined filtrates were concentrate to
afford a brown oil. The oil was purified on the Biotage SP-1 (0-8% ether in hexanes).
TLC revealed that all products were identical (white solids) and all products were
combined. (Yield: 17.10 g of white solid, compound
92 (72%). 1H NMR (CDCl
3) δ: 8.26 (bs, NH), 7.48-7.48 (d, 1H, J = 1.2 Hz), 7.46 -7.43 (d, 1H, J = 8.7 Hz),
7.31 - 7.29 (t, 1H, J = 2.7), 7.04 -7.00 (dd, 1H, J = 2.1, 8.4), 6.61 (s, 1H), 5.92
(s, 2H), 2.05 (s, 6H). MS-ESI m/z (%): 211 (M
+, 100).
[0272] (R)-benzyl 2-(5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indole-3-carbonyl)pyrrolidine-1-carboxylate
(94) (
Macor et. al. J. Org. Chem. 1994, 59(24), 7496):
- a) Formation of (R)-benzyl 2-(chlorocarbonyl)pyrrolidine-1-carboxylate (93): To an argon purged round bottom flask containing N-(benzyloxycarbonyl)-D-proline (10.00 g, 40.1 mmol) was added anhydrous dichloromethane
(120 mL). The translucent reaction was treated with DMF (0.5 mL). Oxalyl chloride
(5.25 mL, 60.2 mmol) was added gradually, resulting in effervescence. The react was
stirred at room temperature under argon for 4 hours. The reaction was concentrate
under reduced pressure and dried overnight under high vacuum to give an oil. The material
was used as is in the next step.
- b) To an argon purged 500 mL round bottom flask fitted with a magnetic stirbar and
containing 93 (16.86 g, 80.2 mmol) was added anhydrous benzene (100 mL). The solution was placed
in an ice-water bath and stirred for 10 minutes. A 3N ethyl magnesium bromide solution
in diethyl ether (28 mL, 84 mmol) was added and the reaction stirred for 30 minutes,
resulting in a dark yellow solution. A solution of 93 in benzene (50 mL) was added slowly by cannula over a period of 5 minutes. The reaction
was stirred in an ice-water bath for 2 hours, becoming dark red in colour. The reaction
was transferred to a separatory funnel and treated with saturated aqueous sodium bicarbonate
solution (50 mL) and ethyl acetate (50 mL). The aqueous layer became milky and translucent
Additional sodium bicarbonate solution (30 mL) did not allow the precipitate to dissolve,
however the phase boundary between the layers became more obvious. The aqueous layer
was removed, and the organic layer poured out as a yellow solution by decantation.
The aqueous layer was filtered to remove the solid, and the resulting colourless solvent
was partitioned twice more with ethyl acetate (2x30 mL). The combined organics were
washed with brine, dried over magnesium sulfate and filtered. The filtrate was concentrate
to afford a yellow oil. The oil was treated with ether (100 mL). After stirring for
15 minutes an off white solid had formed. The reaction was stirred for 1 hr. The precipitate
which formed was collected by vacuum filtration and dried under high vacuum. It was
purified by filtration through a plug of silica gel using ether, followed by ethyl
acetate, as eluents. Yield: 9.5g of white solid, compound 94 (from precipitate). 1H NMR (CDCl3) δ: 9.54, 9.20 (2s, 1H), 8.29-8.28 and 8.15-8.15 (2d, 1H, J=1.2 Hz), 7.81-7.80 and
7.76-7.75 (2d, 1H, J=2.7 Hz), 7.42 -7.30 (m, 4H), 7.13 - 6.93 (m, 3H), 5.90 (bs, 2H),
5.25-4.97 (m, 3H), 3.80 - 3.58 (m, 2H), 2.41- 2.20 (m, 1H), 2.16 -1.88 (m, 2H), 2.04
-1.99 (d, 8H), 1.64 (m, 1H). MS-ESI m/z (%) 442 (M+, 100). (R)-5-(2,5-dimethyl-1H-pyrrol-1-yl)-3-(1-methylpyrrolidin-2-yl)methyl)-1H-indole (95) (Macor et. al. J. Org. Chem. 1994, 59(24), 7496): To an argon purged round bottom flask containing a magnetic stirbar and a solution
of lithium aluminum hydride (1.93 g, 50.9 mmol) in anhydrous THF (20 mL) was added
a solution of 94 (5.00 g, 11.3 mmol) in anhydrous THF (30 mL). The flask was fitted with a condenser
and placed in an oil bath. The reaction was heated to 75°C and stirred at reflux with
an argon flow for 4.5 hrs. The reaction was judged to be complete by TLC (10% 2M NH3 in methanol, 90% CH2Cl2) and was cooled gradually to room temperature. The reaction was cooled further by
placing the flask in an ice-water bath, followed by the portion-wise addition of solid
sodium sulfate decahydrate (20g). The reaction was diluted with cold water (50 mL)
followed by ethyl acetate (50 mL) and the mixture stirred under argon for 17 hrs.
The reaction was transferred into a separatory funnel. Residual solid in the flask
was washed with both water and ethyl acetate and the washes transferred to the funnel.
The aqueous layer was extracted twice more with ethyl acetate. The combined organics
were washed with brine, dried over sodium sulfate and concentrated after decanting
to afford a yellow oil. The product was purified by silica gel column chromatography
(10% 2M NH3 in methanol, 90% CH2Cl2) to afford the desired product as well as some recovered starting material. Yield:
1.827 g of white solid, compound 95 (52.5%). 1H NMR (CDCl3) δ: 8.26 (bs, 1H), 7.45 -7.44 (d, 1H, J=1.5 Hz), 7.41 -7.38 (d, 1H, 8.7 Hz), 7.13
-7.12 (d, 1H, J = 2.1 Hz), 7.02 - 6.99 (dd, 1H, J = 1.8, 8.1 Hz), 5.92 (bs, 2H), 3.49
(s, 1H), 3.20 - 3.12 (m, 2H), 2.68-2.61 (q, 1H, J = 9.3, 14.1 Hz), 2.52-2.40 (m, 1H),
2.44 (s, 3H), 2.28 - 2.19 (q, 1H, J = 9, 17.1 Hz), 2.05 (bs, 6H), 1.89 - 1.56 (m,
4H). MS-ESI m/z (%): 308 (M+, 100).
[0273] (
R)-3-((1-methylpyrrolidin-2 yl)methyl)-1H-indol-5-amine (96) (
Macor et. al. J. Org. Chem. 1994, 59(24), 7496): To an argon purged round bottom flask fitted with a magnetic stirbar and containing
a yellow solution of
95 (1.80 g, 5.85 mmol) in anhydrous 2-propanol (50 mL) and water (15 mL) was added solid
hydroxylamine hydrochloride (8.14g, 117.1 mmol) in one portion. Triethylamine (8.15
mL, 58.5 mmol) was added via syringe and the flask was fitted with a condensor. The
vessel was placed in an oil bath and heated to reflux. The reaction was stirred at
reflux under argon for 5 hours. TLC (10% 2M NH
3 in methanol, 90% CH
2Cl
2) revealed some starting material was still present. The reaction was cooled to room
temperature and stirred overnight. The reaction was returned to reflux and stirred
for an additional 2 hours. The reaction was cooled to room temperature and sodium
hydroxide pellets (2.34 g, 58.5 mmol) were added slowly. The reaction was stirred
vigorously for 17.5 hours and the orange solution became yellow with a white precipitate.
The reaction was filtered through celite, followed by washing of the celite with 2-propanol
(40 mL) and concentration of the filtrate. The residue was purified by column chromatography
(10% 2M NH
3 in methanol, 90% CH
2Cl
2) using a silica gel plug approximately 10 cm in diameter by 15 cm in height to afford
an orange oil. This product was partitioned between brine (5 mL) and ethyl acetate
(20 mL). The organic layer was dried with anhydrous sodium sulfate before being decanted.
Concentration afforded an orange oil, compound
96 (815 mg, 60%).
[0274] (R)-N-(3-((1-methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)thiophene-2-carboximidamide
dihydrochloride (97): To an argon purged round bottom flask was charged
96 (350 mg, 1.53 mmol) and methyl thiophene-2-carbimidothioate hydroiodide (870 mg,
3.05 mmol) followed by absolute ethanol (10 mL). The reaction was stirred using a
magnetic stirbar for 18 hours at room temperature. TLC (10% 2M ammonia in methanol/90%
dichloromethane) revealed all starting amine had reacted. The reaction as treated
with ether (70 mL) and the resulting yellow precipitate was collected by vacuum filtration
and washed with ether. The precipitate was washed from the filter using a solution
of 1N sodium hydroxide (10 mL) followed by ethyl acetate (20mL). This filtrate was
transferred to a separatory funnel, and after agitation, the aqueous phase removed.
The organics were collected, and the aqueous washed twice more with ethyl acetate
(2x10 mL). The combined organic factions were washed with brine, dried over magnesium
sulfate, filtered and concentrated to afford a yellow oil. The product was purified
by silica gel column chromatography (5-10% 2M ammonia in methanol/95-90% dichloromethane)
to afford a yellow oil. The purified product was dissolved in anyhydrous dichloromethane
(5 mL) and treated with 1M hydrogen chloride in ether (5 mL). After stirring for 30
minutes the precipitate was collected by vacuum filtration. The precipitate was washed
with ether, dried under suction and dried further under high vacuum to provide compound
97 (470 mg of yellow solid, 74.7%). 1H NMR (DMSO-
d6) δ: 10.587 (s, 1H), 7.71-7.70 (d, J = 3Hz, 1H), 7.59-7.58 (d, J=4.8Hz, 1H), 7.28-7.25
(d, J=8.4 Hz, 1H), 7.11-7.10 (d, J=4.5Hz, 1H), 7.07-7.06 (d, J=1.5Hz, 1H), 6.93 (s,
1H), 6.64-6.62 (d, J=8.1 Hz, 1H), 6.21 (bs, 2H), 3.18-3.16 (d, J = 5.Hz, 1H), 3.03-2.94
(m, 2H), 2.44-2.33 (m, 4H), 2.14-2.05 (m, 1H), 1.71-1.30 (m, 4H). ESI-MS m/z (%):
339 (M+1, 100).
Example 27. N-(3-(4-(methylamino)cyclohex-1-enyl)-1H-indol-5-yl)thionhene-2-carboximidamide (100)
[0275]
tert-Butyl methyl(4-(5-nitro-1H-indol-3-yl)cyclohex-3-enyl)carbamate (81):
[0276] Please see Example 23 for synthetic details.
tert-Butyl 4-(5-amino-1H-indol-3-yl)cyclohex-3-enyl(methyl)carbamate (98):
[0277] A solution of compound
81 (0.5 g, 1.346 mmol) in dry methanol (20 mL) was treated with hydrazine hydrate (0.41
mL, 13.461 mmol) followed by Raney-Ni (0.1 g) and the resulting mixture was refluxed
for 30 min. The reaction was brought to room temperature, filtered through celite
bed, washed with CH
2Cl
2: methanol (1:1, 3 × 20 mL). The combined organic layer was evaporated and crude was
purified by column chromatography (EtOAC: Hexanes, 1:1) to obtain compound
98 (0.43 g, 94%) as a foam.
1H NMR (DMSO-
d6) δ: 1.38-1.41 (m, 11H), 1.76-1.86 (m, 2H), 2.14-2.42 (m, 2H), 2.73 (s, 3H), 4.05-4.15
(m, 1H), 4.49 (s, 2H), 6.00 (brs, 1H), 6.48 (dd, 1H,
J = 1.8, 8.2 Hz), 6.99 (d, 1H,
J = 1.5 Hz), 7.05 (d, 1H,
J = 8.4 Hz), 7.16 (d, 1H,
J = 2.7 Hz), 10.60 (s, 1H); ESI-MS m/z (%): 364 (M+Na
+, 7), 342 (MH
+, 11), 286 (100).
[0278] tert-Butyl methyl(4-(5-(thiophene-2-carboximidamido)-1H-indol-3-yl)cyclohex-3-enyl)carbamate
(99): A solution of compound
98 (0.415 g, 1.215 mmol) in dry ethanol (20 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.693 g, 2.430 mmol) at room temperature and the resulting
solution was stirred for 24 h. The solvent was evaporated and crude was diluted with
sat. NaHCO
3 solution (25 mL) and CH
2Cl
2 (50 mL). The organic layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 25 mL). The combined organic layer was washed with brine (20 mL) and dried (Na
2SO
4). Th solvent was evaporated and crude product was purified by column chromatography
on silica gel (2M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
99 (0.37 g, 68%) as a foam.
1H NMR (DMSO-
d6) δ: 0.85 (t, 1H,
J = 7.2 Hz), 1.20-1.26 (m, 1H), 1.40 (s, 9H), 1.77-1.87 (m, 2H), 2.22-2.40 (m, 2H),
2.72 (s, 3H), 4.06-4.16 (m, 1H), 6.06 (s, 1H), 6.28 (brs, 1H), 6.66 (d, 1H,
J = 8.4 Hz), 7.10 (t, 1H,
J = 4.2 Hz), 7.22 (s, 1H), 7.25-7.32 (m, 2H), 7.60 (d, 1H,
J = 4.8 Hz), 7.72 (d, 1H,
J = 3.3 Hz), 10.94 (s, 1H); ESI-MS m/z (%): 451 (MH
+, 100).
[0279] N-(3-(4-(methylamino)cyclohex-1-enyl)-1H-indol-5-yl)thiophene-2-carboximidamide (100): A solution of compound
99 (0.35 g, 0.776 mmol) was treated with 20% TFA in CH
2Cl
2 (20 mL) at 0 °C and stirring was continued for 1 h at the same temperature. The solvent
was evaporated and crude was diluted with 10% aq. NH
3 (15 mL) and product was extracted into CH
2Cl
2 (3 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (10 mL) and dried (Na
2SO
4). The solvent was evaporated and the crude product was purified by column chromatography
(2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
100 (0.2 g, 74%) as a solid. mp 167-169 °C;
1H NMR (DMSO-
d6) δ: 1.39-1.47 (m, 2H), 1.88-1.96 (m, 3H), 2.33 (s, 3H), 2.40-2.46 (m, 1H), 2.57-2.61
(m, 1H), 6.01 (s, 1H), 6.19 (brs, 2H), 6.65 (dd, 1H,
J = 1.5, 8.2 Hz), 7.09 (dd, 1H,
J = 4.2, 4.9 Hz), 7.20 (s, 1H), 7.28-7.31 (m, 2H), 7.59 (d, 1H,
J = 4.2 Hz), 7.71 (d, 1H,
J = 3.3 Hz), 10.87 (s, 1H); ESI-MS m/z (%): 351 (MH
+, 66), 320 (54), 160 (63), 119 (100); ESI-HRMS calculated for C
20H
23N
4S (MH
+), Calculated: 351.1654; Observed: 351.1637.
Example 28. (S)-N-(3-((1-methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)thiophene-2-carboximidamide
(105):
[0280]
- a) 5-(2,5-dimethyl-1H-pyrrol-1-yl)-1h-indole (92): See Example 26 for experimental details.
- b) (S)-Benzyl 2-(5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indole-3-carbonyl)pyrrolidine-1-carboxylate
(102): (Macor et. al. J. Org. Chem. 1994, 59(24), 7496). In a similar fashion to the synthesis of 94, Example 26, compound 102 was isolated as an off white foam (4.35 g, 49%). 1H NMR (CDCl3) δ: 9.46, 9.12 (2s, 1H), 8.28-8.28 and 8.16-8.16 (2d, 1H, J=1.2 Hz), 7.86-7.85 and
7.78-7.77 (2d, 1H, J=2.7 Hz), 7.44 - 7.34 (m, 4H), 7.14 - 6.96 (m, 3H), 5.90 (bs,
2H), 5.25-4.97 (m, 3H), 3.80 - 3.58 (m, 2H), 2.41 - 2.20 (m, 1H), 2.16 -1.88 (m, 2H),
2.04 -1.99 (d, 8H), 1.64 (m, 1H). MS-ESI m/z (%): 442 (M+, 100).
[0281] (S)-5-(2,5-dimethyl-1H-pyrrol-1-yl)-3-((1-methylpyrrolidin-2-yl)methyl)-1H-indole
(103): (
Macor et. al. J. Org. Chem. 1994, 59(24), 7496). ). In a similar fashion to the synthesis of 95, Example 26, compound
103 was isolated as a white foam, 1.26 grams (44%). 1H NMR (CDCl
3) δ 8.11 (bs, 1H), 7.45 - 7.44 (d, 1H, J=1.5 Hz), 7.41- 7.38 (d, 1H, 8.7 Hz), 7.12-7.11
(d, 1H, J = 2.1 Hz), 7.03 - 6.99 (dd, 1H, J = 1.8, 8.1 Hz), 5.92 (bs, 2H), 3.18 -
3.09 (m, 2H), 2.65 -2.57 (q, 1H, J = 9.3,14.1 Hz), 2.42 (s, 4H), 2.28 - 2.19 (q, 1H,
J = 9, 17.1 Hz), 2.05 (s, 6H), 1.89 -1.56 (m, 4H).
[0282] (S)-3-(1-methylpyrrolidin-2-yl)methyl)-1H-indol-5-amine (104). In a similar fashion to the synthesis of
96, Example 26, compound
104 was isolated as a brown oil, 149 mg (86%). 1H NMR (CDCl
3) is consistent with previous literature (
Macor et. al. J. Org. Chem. 1994, 59(24), 7496).
[0283] (S)-N-(3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)thiophene-2-carboximidamide
(105): In a similar fashion to the synthesis of
97, Example 26, treatment of
105 with methyl thiophene-2-carbimidothioate hydroiodide in ethanol gave the final product
after purification as an orange solid (62 mg, 77%). 1H NMR (HCl salt) (DMSO-
d6) (11.45 (d, J=19.8Hz, 1H), 10.89 (m, 1H), 9.69 (bs, 1H), 8.63 (bs, 1H), 8.19 - 8.17
(d, J=4.2 Hz, 2H), 7.72-7.69 (m, 1H), 7.56-7.53 (d, J=8.4 Hz, 1H), 7.48-7.47 (d, J
= 1.5Hz, 1H), 7.41-7.38 (t, J = 4.5 Hz, 1H), 7.17-7.14 (d, J=8.4 Hz, 1H), 3.58 (m,
2H), 3.43 -3.37 (m, 1H),3.17 (s, 1H), 3.11-2.99 (m, 2H), 2.81-2.80 (d, J=4.8Hz, 3H),
2.10 -1.70 (m, 5H), 1.28 - 1.23 (m, 3H), 0.90 - 0.85 (m, 2H). ESI-MS: MH
+= 339 (100).
Example 29. Preparation of (R)-N-(3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)furan-2-carboximidamide (106)
[0284]
[0285] (R)-3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-amine) (96): See Example 26 for experimental details.
[0286] (R)-N-(3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)furan-2-carbozimidamide (106): In a like fashion to compound
97, Example 26, using benzyl furan-2-carbimidothioate hydrobromide generated the title
compound
106. (brown solid, 86 mg, 51.8 % yield). 1H NMR (DMSO-
d6) δ: 10.68 (s, 1H), 7.84 (s, 1H), 7.31-7.28 (d, J = 8.4 Hz, 1H), 7.28 (s, 1H), 7.11
(s, 1H), 7.07-7.06 (d, J = 2.7 Hz, 1H), 6.74 - 6.71 (d, J = 6.9 Hz, 1H), 6.65 (s,
1H), 3.18 - 3.16 (d, J = 4.5 Hz, 1H).
Examples 30. (S)-N-(3-((1-methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)furan-2-carboximidamide
dihydrochloride (107):
[0287]
[0288] (S)-3-((1-Methylpyrrolidin-2-yl)methyl)-1H-indol-5-amine) (104): See Example 28 for experimental details.
[0289] (S)-N-(3-((1-methylpyrrolidin-2-yl)methyl)-1H-indol-5-yl)furan-2-carbozimidamide dihydrochloride
(107): In a like fashion to compound
105, Example 28, using benzyl furan-2-carbimidothioate hydrobromide generated the title
compound
107 as pale orange solid (63 mg, 25%). 1H NMR (di-HCl salt) (DMSO-
d6) δ: 11.60 (s, 1H), 11.41-11.40 (d, J=1.2Hz, 1H), 11.09 (bs, 1H), 9.71 (bs, 1H), 8.66
(bs, 1H), 8.25 (s, 1H), 7.99-7.97 (d, J=3.6 Hz, 1H), 7.70 (s, 1H), 7.55-7.52 (d, J=8.7
Hz, 1H), 7.48 - 7.47 (d, J = 1.8Hz, 1H), 7.13-7.10 (dd, J=1.8, 9 Hz, 1H), 6.94 - 6.92
(dd, J=1.2, 3.6 Hz, 1H), 3.74 (m, 3H), 3.61 - 3.54 (m, 3H),3.17 (s, 1H), 3.43-3.37
(dd, J = 4.8, 13.8 Hz, 1H), 3.17 (s, 2H), 3.12-2.98 (m, 2H), 2.80-2.79 (d, J=4.5Hz,
3H), 2.10 -1.70 (m, 5H), 1.28 - 1.23 (m, 3H), 0.90 - 0.85 (m, 2H).
Example 31. N-(3-(1-methylpyrrolidin-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (110) and
N-(3-(1-methylpyrrolidin-3-yl)-1H-indol-5-yl)furan-2-carboximidamide (111):
[0290]
a) N-benzyl-3-(1-methylpyrrolidin-3-yl)-1H-indol-5-amine (108): Macor, J. E et.al J. Med. Chem., 37, 2509-2512, (1994).
(b) N-benzyl-3-(1-methylpyrrolidin-3-yl)-1H-indol-5-amine (110): N-benzyl-3-(1-methylpyrrolidin-3-yl)-1H-indol-5-amine 108, (500 mg, 1.637 mmol) was dissolved in anhydrous ethanol (10 mL) in a dry argon purged
flask. Palladium hydroxide, 20wt% on carbon, wet (560 mg, 0.796 mmol) is quickly added
and the atmosphere from the flask evacuated by vacuum pump and replaced with hydrogen
from a balloon. The atmosphere is evacuated from the flask and replaced with hydrogen
twice more and the mixture stirred under a hydrogen atmosphere at room temperature.
After 48 hours, thin layer chromatography in a solvent system of (10% 2M NH3 in methanol/ 90% dichloromethane) shows approximately 80-85% conversion to 109, 3-(1-methylpyrrolidin-3-yl)-1H-indol-5-amine. The mixture is filtered through a
pad of celite to remove insolubles, the pad washed with anhydrous ethanol (10 mL)
and the solvent evaporated and compound dried briefly on vacuum pump. The crude amine
is dissolved in anhydrous ethanol (20 mL) and batch split into two portions. One half
of the ethanolic solution of 109 (10 mL) is charged to a small, argon purged flask fitted with a magnetic stir bar.
Thiophene-2-carboximidothioic acid methyl ester hydroiodide (350 mg, 1.227 mmol) is
added to the flask and the reaction was stirred under Ar at ambient temperature for
96 hours, at which time the solvent was evaporated and the residue was partitioned
between H2O and ethyl acetate and 1M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered, concentrated and the
residue purified via chromatography on silica gel (5% 2M NH3 in methanol/95% dichloromethane to 15% 2M NH3 in methanol/ 85% dichloromethane) to yield a pale yellow solid 110 (96 mg, 36.2% yield); 1H NMR (DMSO-d6) δ: 10.59 (br s, 1H), 7.71 (d, 1H, J = 3.2), 7.59 (d, 1H, J = 5.1), 7.27 (d, 1H,
J =8.5), 7.14-7.05 (2 x m, 2H), 7.02 (s, 1H), 6.64 (dd, 1H, J = 8.3,1.5), 6.27 (br
s, 2H), 3.56-3.45 (m, 1H), 2.93 (t, 1H, J = 8.4), 2.72-2.65 (m, 1H), 2.58-2.50 (m,
2H), 2.31 (s, 3H), 2.28-2.15 (m, 1H), 1.98-1.86 (m, 1H); MS (ESI+): 325 (M+1, 100%).
ESI-HRMS calculated for C18H21N4S (MH+): 325.1488, Observed: 325.1481.
c) N-(3-(1-methylpyrrolidin-3-yl)-1H-indol-5-yl)furan-2-carboximidamide (111): The remaining half of the ethanolic solution of 109 (10 mL, see above) is charged to a small, argon purged flask fitted with a magnetic
stir bar. Benzyl furan-2-carbimidothioate hydrobromide (366 mg, 1.227 mmol) is added
to the flask and the reaction was stirred under Ar at ambient temperature for 24 hours,
at which time the solvent was evaporated and the residue was partitioned between H2O and ethyl acetate and 1M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered, concentrated and the
residue purified via chromatography on silica gel (5% 2M NH3 in methanol/ 95% dichloromethane to 20% 2M NH3 in methanol/80% dichloromethane) to yield a pale yellow foam 111 (170 mg, 67.4% yield);
1H NMR (DMSO-d6) δ: 10.61 (br s, 1H), 7.80 (s, 1H), 7.27 (d, 1H, J = 8.5), 7.17-7.04 (2 x m, 3H),
6.68 (d, 1H, J = 8.2), 6.62 (s, 1H), 6.40 (br s, 1H), 3.55-3.44 (m, 1H), 2.94 (t,
1H, J = 8.3), 2.74-2.66 (m, 1H), 2.59-2.50 (m, 2H), 2.31 (s, 3H), 2.28-2.16 (m, 1H),
1.97-1.86 (m, 1H); MS (ESI+): 309 (M+1, 100%). ESI-HRMS calculated for C18H21N4O (MH+): 309.1717, Observed: 309.1709.
Example 32. N-(3-(4-(dimethylamino)cyclohex-1-enyl)-1H-indol-5-yl)thiophene-2-carboximidamide (114):
[0291]
[0292] 5-Nitro-3-(1,4-diozaspiro[4.5]dec-7-en-8-yl)-1H-indole (78): A solution of 5-nitroindole (
38) (3.0 g, 18.501 mmol) in dry methanol (50 mL) was treated with KOH (5.6 g) at room
temperature. After stirring for 10 min., 1, 4-cyclohexanedione monoethylene ketal
(7.22 g, 46.253 mmol) was added and the resulting solution was refluxed for 36 h.
The reaction was brought to room temperature and solvent was evaporated. Crude was
diluted with water (50 mL), precipitated solid was filtered off and washed with water
(2 × 10 mL). The precipitate was dried under vacuum to obtain compound
78 (4.7 g, 85%) as a solid. For spectral data, please see Example 23.
[0293] 4-(5-Nitro-1H-indol-3-yl)cyclohex-3-enone (79): A solution of compound
78 (4.7 g, 15.650 mmol) in acetone (50 mL) was treated with 10 % aq. HCl (50 mL) at
room temperature and stirred for over night (14h). Acetone was evaporated and crude
was basified using 10% aq. NH
4OH solution (100 mL). The precipitate was filtered off, washed with 10% NH
4OH solution (2 ×10 mL) and water (2 × 10 mL). The product was dried under vacuum to
obtain compound
79 (4.0 g, quantitative) as a solid. For spectral data, please see Example 23.
[0294] N,N-Dimethyl-4-(5-nitro-1H-indol-3-yl)cyclohex-3-enamine (112): A solution of compound
79 (1.0 g, 3.902 mmol) in dry 1,2-dichloroethane (10 mL) was treated with N, N-dimethyl
amine hydrochloride (0.31 g, 3.902 mmol), AcOH (0.22 mL, 3.902 mmol), NaBH(OAc)
3 (1.24 g, 5.853 mmol) at room temperature and the resulting mixture was stirred for
overnight (14h). The reaction was diluted with 1 N NaOH (30 mL) and product was extracted
into ethyl acetate (2 × 50 mL). The combined ethyl acetate layer was washed with brine
(20 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
112 (0.73 g, 66%) as a brown solid. mp 234-236 °C;
1H NMR (DMSO-
d6) δ 1.43-1.57 (m, 1H), 1.98-2.06 (m, 1H), 2.12-2.23 (m, 7H), 2.39-2.62 (m, 4H), 6.15
(t, 1H, J= 1.5 Hz), 7.54 (d, 1H,
J = 9.0 Hz), 7.62 (s, 1H), 8.00 (dd, 1H,
J = 2.1, 9.0 Hz), 8.67 (d, 1H,
J = 2.1 Hz), 11.82 (s, 1H); ESI-MS m/z (%): 286 (MH
+, 100).
[0295] 3-(4-(Dimethylamino)cyclobex-1-enyl)-1H-indol-5-amine (113): A solution of compound
112 (0.21 g, 0.735 mmol) in dry methanol (5 mL) was treated with Ra-Ni (0.05 g) followed
by hydrazine hydrate (0.22 mL, 7.359 mmol) at room temperature. The reaction was placed
in a pre-heated oil bath and refluxed for 5 min. The reaction brought to room temperature,
filtered through celite bed and washed with methanol (2 × 10 mL). The solvent was
evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
113 (0.185 g, quantitative) as a foam. mp 63-65 °C;
1H NMR (DMSO-
d6) δ 1.40-1.52 (m, 1H), 1.97-2.02 (m, 1H), 2.08-2.57 (m, 11H), 4.47 (s, 2H), 5.99 (brs,
1H), 6.47 (dd, 1H,
J = 1.8, 8.4 Hz), 6.99 (d, 1H,
J = 0.9 Hz), 7.04 (d, 1H,
J = 8.7 Hz), 7.13 (d, 1H,
J = 2.4 Hz), 10.55 (s, 1H); ESI-MS m/z (%): 256 (MH
+, 100),211 (41).
[0296] N-(3-(4-(dimethylamino)cyclohex-1-enyl)-1H-indol-5-yl)thiophene-2-carboximidamide
(114): A solution of compound
113 (0.18 g, 0.704 mmol) in dry ethanol (10 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.4 g, 1.409 mmol) at room temperature and stirred
for 24 h. Solvent was evaporated and crude was diluted with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 25 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2 1:9) to obtain compound
114 (0.24 g, 90%) as a solid. mp 113-115°C;
1H NMR (DMSP-
d6) δ 1.42-1.53 (m, 1H), 1.97-2.02 (m, 1H), 2.08-2.22 (m, 8H), 2.31-2.60 (m, 3H), 6.03
(s, 1H), 6.21 (brs, 2H), 6.65 (dd, 1H,
J = 1.2, 8.4 Hz), 7.09 (t, 1H,
J = 4.2 Hz), 7.20 (s, 1H), 7.28-7.31 (m, 2H), 7.58 (d, 1H,
J = 4.5 Hz), 7.71 (d, 1H,
J = 2.7 Hz), 10.88 (s, 1H); ESI-MS m/z (%): 365 (MH
+, 39), 320 (38), 183 (76), 160 (100); ESI-HRMS calculated for C
21H
25N
4S (MH
+), Calculated: 365.1813; Observed: 365.1794.
Example 33. N-(3-(4-(dimethylamino)cyclohexyl)-1H-indol-5-yl)thiophene-2-carboximidamide (116):
[0297]
[0298] N,N-Dimethyl-4-(5-nitro-1H-indol-3-yl)cyclohex-3-enamine (112): For complete experimental details and spectral data, see Example 32.
[0299] N-(3-(4-(Dimethylamino)cyclohexyl)-1H-indel-5-yl)thiophene-2-carboximidamide (116): A solution of compound
112 (0.43 g, 1.506 mmol) in dry ethanol (5 mL) was treated with 10% Pd-C (0.04 g) and
purged with hydrogen gas at room temperature. The reaction was stirred at the same
temperature under a hydrogen atmosphere (balloon pressure) overnight (14 h). The reaction
was filtered through a celite bed and washed with dry ethanol (2 × 5 mL). The combined
ethanol layer was treated with thiophene-2-carboximidothioic acid methyl ester-hydroiodide
(0.85 g, 3.013 mmol) at room temperature and stirred for 24 h. The solvent was evaporated
and crude material was diluted with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 25 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4)-The solvent was evaporated and crude was purified by column chromatography on silica
gel (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
116 (0.4 g, 72%, over two steps) as a yellow solid. mp 104-106 °C;
1H NMR (DMSO-
d6) δ: 1.39-1.60 (m, 3H), 1.66-1.72 (m, 1H), 1.82-1.94 (m, 3H), 2.05-2.08 (m, 1H), 2.23
(s, 3H), 2.34 (s, 3H), 2.64-2.71 (m, 1H), 2.91-2.96 (m, 1H), 6.48 (brs, 1H), 6.64
(dd, 1H,
J = 1.5, 8.4 Hz), 6.99-7.05 (m, 2H), 7.10 (t, 1H,
J = 4.2 Hz), 7.27 (d, 1H,
J = 8.4 Hz), 7.60 (d, 1H,
J = 5.4 Hz), 7.71 (d, 1H,
J = 3.3 Hz), 10.57 (s, 1H); ESI-MS m/z (%): 367 (MH
+, 31), 322 (18), 184 (100); ESI-HRMS calculated for C
21H
27N
4S (MH
+), Calculated: 367.1965; Observed: 367.1950.
Example 34. N-(3-(4-(ethylamino)cyclohexyl)-H-indol-5-yl)thiophene-2-carboximidamide (121):
[0300]
[0301] 4-(5-Nitro-1H-indol-3-yl)cyclohex-3-enone (79): See Example 23 for complete experimental details and spectral data.
[0302] N-Ethyl-4-(5-nitro-1H-indol-3-yl)cyclohex-3-enamine (117): A solution of compound
79 (1.0 g, 3.902 mmol) in dry 1,2-dichloroethane (10 mL) was treated with ethylamine
hydrochloride (0.31 g, 3.902 mmol), glacial acetic acid (0.22 mL, 3.902 mmol) and
NaBH(OAc)
3 (1.24 g, 5.853 mmol) at room temperature and the resulting mixture was stirred for
overnight (14 h). The reaction was diluted with 1 N NaOH (30 mL) and product was extracted
into ethyl acetate (2 × 50 mL). The combined ethyl acetate layer was washed with brine
(20 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:9) to obtain compound
117 (1.08 g, 97%) as a dark yellow solid. mp 177-179 °C;
1H NMR (DMSO-
d6) δ: 1.03 (t, 3H,
J = 6.9 Hz), 1.39-1.52 (m, 2H), 1.94-2.00 (m, 2H), 2.40-2.80 (m, 3H), 3.16 (s, 2H),
4.07 (brs, 1H), 6.13 (s, 1H), 7.54 (d, 1H,
J = 9.0 Hz), 7.62 (s, 1H), 8.00 (dd, 1H,
J = 2.4, 9.0 Hz), 8.67 (d, 1H,
J = 2.4 Hz), 11.83 (brs, 1H); ESI-MS m/z (%): 286 (MH
+, 100).
[0303] tert-Butyl ethyl(4-(5-nitro-1H-indol-3-yl)cyclohex-3-enyl)carbamate (118): A solution of compound
117 (1.05 g, 3.679 mmol) in dry 1,4-dioxane (20 mL) was treated with Et
3N (1.02 mL, 7.359 mmol) followed by (Boc)
2O (0.84 g, 3.863 mmol) at room temperature and the resulting solution was stirred
for overnight (14 h). Solvent was evaporated and crude was purified by column chromatography
on silica gel (2 M NH
3 in methanol: CH
2Cl
2, 1:1) to obtain compound
118 (1.1 g, 78%) as a yellow solid. mp 217-219 °C;
1H NMR (DMSO-
d6) δ 1.09 (t, 3H,
J = 6.9 Hz), 1.42 (s, 9H), 1.83-1.96 (m, 2H), 2.27-2.43 (m, 2H), 2.56-2.62 (m, 2H),
3.14-3.18 (m, 2H), 4.05 (brs, 1H), 6.16 (s, 1H), 7.55 (d, 1H,
J = 9.0 Hz), 7.64 (s, 1H), 8.01 (dd, 1H,
J = 2.1, 8.7 Hz), 8.67 (d, 1H,
J = 2.1 Hz), 11.85 (s, 1H); ESI-MS m/z (%): 408 (M+Na, 95), 386 (MH
+, 9), 330 (73), 286 (100).
[0304] tert-Butyl 4-(5-amino-1H-indol-3-yl)cyclohexyl(ethyl)carbamate (119): A solution of compound
118 (0.55 g, 1.427 mmol) in 2 M NH
3 in methanol (10 mL) was treated with Pd-C (0.05 g) and flushed with hydrogen gas.
The reaction was stirred at room temperature overnight (16 h) under hydrogen atmosphere
(balloon pressure). The solution was filtered through a celite bed using methanol
washes (2 x 10 mL). The solvent was evaporated and crude was purified by column chromatography
(2 M NH
3 in methanol: CH
2Cl
2, 2.5:97.5) to obtain compound
119 (0.43 g, 84%) as a solid in 2:3 ratio of diastereomers.
1H NMR (DMSO
-d6) δ: 0.99, 1.07 (2t, 3H,
J = 7.2, 6.6 Hz), 1.37-1.51 (m, 11H), 1.63-1.78 (m, 4H), 2.01-2.18 (m, 2H), 2.98-3.04
(m, 1H), 3.11-3.17 (m, 2H), 3.68-3.80 (m, 1H), 4.52 (brs, 2H), 6.44-6.47 (m, 1H),
6.66-6.70 (m, 1H), 6.86-6.88, 6.99-7.06 (2m, 2H), 10.23, 10.27 (2s, 1H); ESI-MS m/z
(%): 380 (M+Na, 6), 358 (MH
+, 5), 302 (100), 258 (54); ESI-HRMS calculated for C
21H
32N
3O
2 (MH
+), Calculated: 358.2507; Observed: 358.2489.
[0305] tert-Butyl ethyl(4-(5-(thiophene-2-carboximidamido)-1H-indol-3-yl)cyclohexyl)carbamate
(120): A solution of compound
119 (0.4 g, 1.119 mmol) in dry ethanol (20 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.63 g, 2.239 mmol) at room temperature and stirred
for 24 h. The solvent was evaporated, diluted with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 25 mL). The CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude material was purified by column chromatography
on silica gel (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
120 (0.4 g, 60%) as a yellow solid in 2:3 ratio of cis-trans diastereomers.
1H NMR (DMSO
-d6) δ 0.98-1.08 (m, 3H), 1.38-1.56 (m, 11H), 1.68-1.85 (m, 4H), 2.05-2.18 (m, 2H), 3.02-3.17
(m, 3H), 3.70-3.76 (m, 1H), 6.31 (brs, 2H), 6.62-6.67 (m, 1H), 6.96-7.01 (m, 1H),
7.09-7.11 (m, 1H), 7.22-7.30 (m, 2H), 7.60 (d, 1H,
J = 5.1 Hz), 7.70-7.72 (m, 1H), 10.59, 10.62 (2s, 1H); ESI-MS m/z (%): 467 (MH
+, 100).
[0306] N-(3-(4-(Ethylamino)cyclohexyl)-1H-indol-5-yl)thiophene-2-carboximidamide (
121): Compound
120 (0.26 g, 0.557 mmol) was treated with 1 N aqueous HCl solution at room temperature
and the resulting solution was refluxed for 2 h. The reaction was brought to room
temperature, filtered and washed with water (5 mL). The solvent was evaporated and
crude was recrystallised from ethanol/ether to obtain compound
121 (0.23 g, 94%) as a solid in 2:3 ratio of diastereomers.
1H NMR (DMSO
-d6) δ 1.22-1.29 (m, 3H), 1.53-1.62 (m, 2H), 1.80-2.16 (m, 6H), 2.74-3.23 (m, 4H), 7.08
(d, 1H,
J = 8.4 Hz), 7.24-7.52 (m, 3H), 7.68-7.72 (m, 1H), 8.14-8.18 (m, 2H), 8.59 (s, 1H),
8.97-9.09 (m, 2H), 9.64 (s, 1H), 11.20, 11.27 (2s, 1H), 11.42 (s, 1H); ESI-MS m/z
(%): 367 (MH
+ for free base, 18), 322 (100), 184 (19), 119 (39); ESI-HRMS calculated for C
21H
27N
4S (MH
+, free base), calculated: 367.1959; observed: 367.1950.
Example 35. N-(3-(1-azabicyclo[2.2.2]oct-2-en-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (125),
N-(3-(quinuclidin-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (126) and N-(3-(quinuclidin-3-yl)-1H-indol-5-yl)furan-2-carboximidamide (127):
[0307]
- (a) 3-(5-Nitro-1H-indol-3-yl)-1-azabicyclo[2.2.2]oct-2-ene 1 (122): Schiemann et. al. US Pat App. US2004/012935 A1
- (b) N-(3-(1-azabicyclo[2.2.2]oct-2-en-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (125)
and N-(3-(quinuclidin-3-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (126): 3-(5-Nitro-1H-indol-3-yl)-1-azabicyclo[2.2.2]oct-2-ene (compound 122, 250 mg, 0.928 mmol) was dissolved in anhydrous methanol (10 mL) in a dry argon purged
flask. Palladium, 10 wt% on activated carbon (49.2 mg, 0.0463 mmol) is quickly added
and the atmosphere from the flask evacuated by vacuum pump and replaced with hydrogen
from a balloon. The atmosphere is evacuated from the flask and replaced with hydrogen
twice more and the mixture stirred under a hydrogen atmosphere at room temperature.
After 17 hours, thin layer chromatography in a solvent system of (20% 2M NH3 in methanol/ 80% dichloromethane) shows complete consumption of starting material
122, and a mixture of 2 new products; compound 2, 3-(1-azabicyclo[2.2.2]oct-2-en-3-yl)-1H-indol-5-amine
(123) and 3, 3-(quinuclidin-3-yl)-1H-indol-5-amine (124) in the ratio of 60/40 by TLC. The mixture is filtered through a pad of celite to
remove insolubles, the pad washed with anhydrous methanol (10 mL) and solution of
the two amines split into two portions. One half of the methanolic solution of 123
and 124 is charged to a small, argon purged flask fitted with a magnetic stir bar. Thiophene-2-carboximidothioic
acid methyl ester hydroiodide (172 mg, 0.603 mmol) is added to the flask and the reaction
was stirred under argon at ambient temperature for 24 hours, at which time the solvent
was evaporated and the residue was partitioned between H2O and ethyl acetate and 1M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered, concentrated and the
residue purified via chromatography on silica gel (10% 2M NH3 in methanol/ 90% dichloromethane to 20% 2M NH3 in methanol/ 80% dichloromethane) to yield 2 products; pale yellow solid 125 (50 mg, 31.0% yield); 1H NMR (DMSO) δ: 11.37 (br s, 1H), 7.75 (d, 1H, J = 2.7), 7.72 (d, 1H, J = 2.5), 7.65
(d, 1H, J = 3.8), 7.40 (d, 1H, J = 8.5), 7.19 (m, 1H), 7.15-7.12 (m, 1H), 6.84 (s,
1H), 6.79-6.76 (m, 1H), 6.50 (br s, 2H), 2.97-2.81 (m, 3H), 1.99-1.86 (m, 2H), 1.73-1.60
(m, 2H); MS (ESI+): 349 (M+1, 40%). ESI-HRMS calculated for C20H21N4S (MH+): 349.1495, Observed: 349.1481 and pale yellow solid 126 (65 mg, 40.1% yield); 1H NMR (DMSO) δ: 10.72 (br s, 1H), 7.71 (d, 1H, J = 3.4), 7.59 (d,1H, J = 5.2), 7.30-7.25
(2 x m, 2H), 7.09 (dd, 1H, J = 5.2, 3.8), 6.92 (s, 1H), 6.65 (dd, 1H, J = 8.3, 1.5),
6.20 (br s, 2H), 3.32-3.19 (m, 2H), 3.05-2.99 (m, 2H), 2.95-2.90 (m, 2H), 2.84-2.72
(m, 1H), 1.98-1.79 (2 x m, 2H), 1.72-1.57 (m, 2H), 1.37-1.26 (m, 1H); MS (ESI+): 351
(M+1, 10%), 176 (M++ doubly charged, 100%). ESI-HRMS calculated for C20H23N4S (MH+): 351.1651, Observed: 351.1637.
N-(3-(quinuclidin-3-yl)-1H-indol-5-yl)furan-2-carboximidamide (127):
[0308] A solution containing
123 and
124 (10 mL, 0.465 mmol) in methanol (see above) is charged to a small, argon purged flask
fitted with a magnetic stir bar. Benzyl furan-2-carbimidothioate hydrobromide (207
mg, 0.696 mmol) is added to the flask and the reaction was stirred under argon at
ambient temperature for 48 hours, at which time the solvent was evaporated and the
residue was partitioned between H
2O and ethyl acetate and 1M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered, concentrated and the
residue purified twice via chromatography on silica gel (10% 2M NH
3 in methanol/ 90% dichloromethane to 30% 2M NH
3 in methanol/ 70% dichloromethane) to yield a beige solid
127 (51 mg, 32.9% yield);
1H NMR (DMSO) δ: 10.76 (br s, 1H), 7.79 (s, 1H), 7.31-7.28 (2 x m, 2H), 7.09 (br s,
1H), 6.99 (s, 1H), 6.70 (d, 1H), 6.61 (s, 1H), 3.47-3.27 (m, 2H), 3.09-2.95 (2 x m,
4H), 2.85-2.79 (m, 1H), 1.97-1.81 (2 x m, 2H), 1.78-1.58 (2 x m, 2H), 1.44-1.33 (m,
1H); MS (ESI+): 335 (M+1, 20%), 168 (M++ doubly charged, 100%). ESI-HRMS calculated
for C
20H
23N
4O (MH
+): 335.1866, Observed: 335.1882.
Example 36. N-(3-(3-fluoro-1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(134):
[0309]
tert-Butyl 4-(trimethylsilyloxy)-5,6-dihydropyridine-1(2H)-carboxylate (129):
[0310] A solution of compound
128 (6.0 g, 30.112 mmol) in dry DMF (12 mL) was treated with trimethylsilylchloride (4.58
mL, 36.135 mmol), Et
3N (10.07 mL, 72.271 mmol) at room temperature (Caution: Foaming occurs) and the resulting
solution was stirred at 80 °C for 16 h. The reaction was brought to room temperature
and diluted with hexane (100 mL). The hexane layer was washed with cold saturated
NaHCO
3 solution (3 × 20 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (EtOAc:
Hexanes, 1:9) to obtain compound
129 (4.53 g, 55%) as a liquid with major recovery of starting material (2.6 g).
1H NMR is comparable with literature (
J. Med Chem. 1999, 42, 2087-2104).
tert-Butyl 3-fluoro-4-oxopiperidine-1-carboxylate (130): A solution of compound
129 (4.5 g, 16.578 mmol) in dry acetonitrile (175 mL) was treated with Selectfluor™ (6.46
g, 18.236 mmol) at room temperature and resulting solution was stirred for 75 min.
at same temperature. The reaction was diluted with ethyl acetate (500 mL), washed
with unsaturated brine (300 mL, water: saturated brine 1:1), saturated brine (100
mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (ethyl
acetate to 5% methanol in ethyl acetate) to obtain compound
130 (3.18 g, 88%) as a syrup.
1H NMR (CDCl
3) δ:1.50 (s, 9H), 2.46-2.64 (m, 2H), 3.20-3.37 (m, 2H), 4.13-4.20 (m, 1H), 4.44-4.48
(m, 1H), 4.72-4.77, 4.88-4.93 (2m, 1H).
1H NMR comparable with literature (
J. Med. Chem. 1999, 42, 2087-2104).
[0311] 3-(3-Fluoro-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (131): A solution of 5-nitroindole
(38) (1.0 g, 6.167 mmol) in glacial acetic acid (10 mL) at 90°C was treated with compound
130 (1.33 g, 6.167 mmol) in glacial AcOH (5 mL), 1 M H
3PO
4 in glacial AcOH (5 mL) and the resulting solution was stirred at same temperature
for 16 h. The reaction was brought to room temperature, poured into 15% cold aqueous
ammonia solution (100 mL) and product was extracted into ethyl acetate (2 × 50 mL).
The combined ethyl acetate layer was washed with brine (25 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:99 to 5:95) to obtain compound
131 (0.75 g, 47%) as a yellow solid. mp 205-207 °C;
1H NMR (DMSO
-d6) δ 2.35 (brs, 1H), 2.86-3.06 (m, 1H), 3.19-3.26 (m, 1H), 3.35-3.58 (m, 2H), 5.28
(d, 1H,
J= 49.5 Hz), 6.53-6.56 (m, 1H), 7.58 (d, 1H,
J= 8.7 Hz), 7.74 (s, 1H), 8.02 (dd, 1H,
J= 2.4, 9.0 Hz), 8.68 (d, 1H,
J= 2.4 Hz), 11.94 (s, 1H); ESI-MS m/z (%): 262 (MH
+, 100), 233 (50).
3-(3-Fluoro-1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (132):
[0312] A solution of compound
131 (0.2 g, 0.765 mmol) in dry methanol (5 mL) was treated with formaldehyde (0.07 mL,
0.918 mmol, 37% in water), AcOH (0.1 mL, 1.913 mmol) and NaBH
3CN (0.057 g, 0.918 mmol) at 0 °C. The resulting mixture brought to room temperature
and stirred for 3 h. The reaction was basified with 1 N NaOH (25 mL) and product was
extracted into ethyl acetate (2 × 25 mL). The combined ethyl acetate layer was washed
with brine (20 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 1:99 to 1:9) to obtain compound
132 (0.2 g, 95%) as a yellow solid. mp 94-96 °C;
1H NMR (DMSO
-d6) δ 2.32 (s, 3H), 2.48-2.63 (m, 1H), 2.78-2.87 (m, 1H), 3.03-3.12 (m, 1H), 3.38-3.48
(m, 1H), 5.45 (d, 1H,
J= 48.9 Hz), 6.48-6.50 (m, 1H), 7.58 (d, 1H,
J= 8.7 Hz), 7.75 (s, 1H), 8.03 (dd, 1H,
J = 2.1, 9.0 Hz), 8.68 (d, 1H,
J= 2.1 Hz), 11.96 (s, 1H); ESI-MS m/z (%): 276 (MH
+, 100).
3-(3-fluoro-1-methyl-1,2,3,6-tetrahydropyridin4-yl)-1H-indol-5-amine (133):
[0313] A solution of compound
132 (0.175 g, 0.635 mmol) in dry methanol (5 mL) was treated with hydrazine hydrate (0.198
mL, 6.357 mmol) followed by Ra-Ni (∼ 0.05 g) at room temperature. The reaction was
placed in a pre-heated oil bath and refluxed for 2 min. The reaction was brought to
room temperature, filtered through celite bed, washed with methanol (3 × 10 mL). The
combined methanol layer was evaporated and crude was purified by column chromatography
(2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
133 (0.07 g, 45%) as a solid. mp 176-178 °C;
1H NMR (DMSO
-d6) δ 2.30 (s, 3H), 2.40-2.56 (m, 1H), 2.73-2.83 (m, 1H), 2.99-3.08 (m, 1H), 3.30-3.42
(m, 1H), 4.51 (s, 2H), 5.37 (d, 1H,
J= 48.9 Hz), 6.22-6.26 (m, 1H), 6.51 (dd, 1H,
J= 1.8, 8.5 Hz), 6.97 (d, 1H,
J= 1.8 Hz), 7.08 (d, 1H,
J = 8.4 Hz), 7.27 (t, 1H,
J =1.8 Hz), 10.72 (s, 1H); ESI-MS m/z (%): 246 (MH
+, 12), 203 (100).
[0314] N-(3-(3-fluoro-1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(134): A solution of compound
133 (0.062 g, 0.252 mmol) in dry ethanol (5 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.144 g, 0.505 mmol) at room temperature and stirred
for 20 h. Solvent was evaporated, crude was diluted with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 0:100 to 1:9) to obtain compound 134 (0.052 g, 58%) as a solid. mp 127-129 °C;
1H NMR (DMSO
-d6) δ 2.29 (s, 3H), 2.42-2.57 (m, 1H), 2.72-2.81 (m, 1H), 3.00-3.09 (m, 1H), 3.32-3.42
(m, 1H), 5.41 (d, 1H,
J = 49.2 Hz), 6.30-6.40 (m, 3H), 6.69 (dd, 1H,
J =1.2, 8.4 Hz), 7.10 (t, 1H,
J = 3.9 Hz), 7.22 (s, 1H), 7.34 (d, 1H,
J= 8.4 Hz), 7.42 (s, 1H), 7.60 (d, 1H,
J = 4.8 Hz), 7.73 (d, 1H,
J = 2.7 Hz), 11.05 (s, 1H); ESI-MS m/z (%): 355 (MH
+, 100), 335 (21), 312 (33); ESI-HRMS calculated for C
19H
20FN
4S (MH
+), Calculated: 355.1391; Observed: 355.1387.
Example 37. N-(3-(3-fluoro-1-methylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (137):
[0315]
3-(3-Fluoro-1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-5-nitro-1H-indole (132):
[0316] For complete experimental details, see Example 36.
[0317] 3-(3-Fluoro-1-methylpiperidin-4-yl)-5-nitro-1H-indole (135): A solution of compound
132 (0.22 g, 0.799 mmol) in TFA (5 mL) was treated with triethylsilane (0.22 mL, 1.438
mmol) at room temperature and stirred for 4 h. The reaction was carefully transferred
to a beaker containing sat. NaHCO
3 solution (50 mL) and product was extracted into ethyl acetate (2 × 20 mL). The combined
ethyl acetate layer was washed with brine (10 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 2.5:97.5) to obtain the trans diastereoisomers (mixture of enantiomers) compound
135 (0.102 g, 46%) as a solid. mp 105-107 °C;
1H NMR (DMSO
-d6) δ 1.80-1.96 (m, 2H), 2.02-2.15 (m, 2H), 2.29 (s, 3H), 2.78-2.81 (m, 1H), 2.98-3.09
(m, 1H), 3.16-3.21 (m, 1H), 4.62 (dddd, 1H,
J= 48.6, 4.8, 9.9, 9.9 Hz), 7.50-7.54 (m, 2H), 7.98 (dd, 1H,
J= 2.1, 9.0 Hz), 8.54 (d, 1H,
J= 2.1 Hz), 11.71 (s, 1H); ESI-MS m/z (%): 278 (MH
+, 100).
[0318] 3-(3-Fluoro-1-methylpiperidin-4-yl)-1H-indol-5-amine (136): A solution of compound
135 (0.09 g, 0.324 mmol) in dry methanol (3 mL) was treated with hydrazine hydrate (0.1
mL, 3.245 mmol) followed by Ra-Ni (∼ 0.05 g) at room temperature. The reaction was
placed in a pre-heated oil bath and refluxed for 5 min. The reaction was brought to
room temperature, filtered through celite bed and washed with methanol (2 × 10 mL).
The combined methanol layer was evaporated and crude was purified by column chromatography
(2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
136 (0.08 g, quantitative) as a semi-solid.
1H NMR (DMSO
-d6) δ 1.78-1.86 (m, 2H), 1.95-2.07 (m, 2H), 2.26 (s, 3H), 2.69-2.78 (m, 2H), 3.11-3.17
(m, 1H), 4.41 (s, 2H), 4.68 (dddd, 1H,
J= 4.5, 9.9, 9.9, 48.7 Hz), 6.45 (dd, 1H,
J= 2.1, 8.5 Hz), 6.71 (d, 1H,
J= 1.5 Hz), 6.93-7.04 (m, 2H), 10.36 (s, 1H); ESI-MS m/z (%): 248 (MH
+, 100).
[0319] N-(3-(3-fluoro-1-methylpiperidin-4-yl)-1H-indol-5-yl)thiophene-2-carboximidamide (137): A solution of compound
136 (0.07 g, 0.283 mmol) in dry ethanol (5 mL) was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.16 g, 0.566 mmol) at room temperature and stirred
for overnight (16 h). Solvent was evaporated, crude was diluted with sat. NaHCO
3 solution (25 mL) and product was extracted into CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
137 (0.09 g, 90%) as a solid. mp 115-117 °C;
1H NMR (DMSO
-d6) δ 1.79-2.09 (m, 4H), 2.26 (s, 3H), 2.74-2.90 (m, 2H), 3,13-3.17 (m, 1H), 4.68 (dddd,
1H,
J= 4.8, 9.6, 9.6, 48.5 Hz), 6.23 (brs, 2H), 6.65 (d, 1H,
J= 8.1 Hz), 6.99 (s, 1H), 7.09 (t, 1H,
J= 4.2 Hz), 7.17 (d, 1H,
J = 1.5 Hz), 7.28 (d, 1H,
J = 8.4 Hz), 7.59 (d, 1H,
J = 5.1 Hz), 7.70 (d, 1H,
J = 3.3 Hz), 10.72 (s, 1H); ESI-MS m/z (%): 357 (MH
+, 100), 179 (52); ESI-HRMS calculated for C
19H
22FN
4S (MH
+), Calculated: 357.1547, Observed: 357.1543.
Example 38. N-(3-(1,2,3,5,8,8a-hexahydroindolizin-7-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(142):
[0320]
3-(1,2,3,5,8,8a-Hexahydroindolizin-7-yl)-5-nitro-1H-indole (141):
[0322] A solution of compound
38 (0.4 g, 2.466 mmol) in dry methanol (5 mL) was treated with KOH (1.12 g) at 0 °C
and was stirred at room temperature for 10 min. Compound
140 (0.44 g, 3.206 mmol) in methanol (5 mL) was added and resulting mixture was refluxed
for 30 h. The reaction was brought to room temperature and solvent was evaporated.
Crude was diluted with water (20 mL) and product was extracted into CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was recrystallised from ethanol to obtain compound
V (0.2 g, 29%) as solid. mp 205-207 °C;
1H NMR (DMSO
-d6) δ 1.41-1.52 (m, 1H), 1.70-1.80 (m, 2H), 1.98-2.15 (m, 2H), 2.20-2.40 (m, 2H), 2.61-2.72
(m, 1H), 2.86-2.91 (m, 1H), 3.10-3.15 (m, 1H), 3.66 (dd, 1H,
J = 4.2, 16.5 Hz), 6.20 (s, 1H), 7.55 (d, 1H,
J = 9.0 Hz), 7.67 (s, 1H), 8.01 (dd, 1H,
J =1.8, 9.0 Hz), 8.69 (d, 1H,
J = 2.1 Hz), 11.87 (s, 1H); ESI-MS (m/z, %) 284 (MH
+, 100).
[0323] N-(3-(1,2,3,5,8,8a-Hexahydroindolizin-7-yl)-1H-indol-5-yl)thiophene-2-carboximidamide
(142): A solution of compound
141 (0.12 g, 0.423 mmol) in dry methanol (5 mL) was treated with Ra-Ni (∼ 0.05 g), hydrazine
hydrate (0.13 mL, 4.235 mmol) at room temperature. The resulting mixture was refluxed
for 2 min, in pre-heated oil bath. The reaction was brought to room temperature, filtered
through celite bed and washed with methanol (2 × 20 mL). The combined methanol layer
was evaporated and crude was purified by column chromatography (2 M NH
3 in MeOH: CH
2Cl
2, 95:5) to obtain 3-(1,2,3,5,8,8a-Hexahydroindolizin-7-yl)-1H-indol-5-amine, (0.087
g, 81 %) as a solid. mp 208-210 °C;
1H NMR (DMSO
-d6) δ 1.33-1.48 (m, 1H), 1.67-1.79 (m, 2H), 1.94-2.13 (m, 2H), 2.16-2.26 (m, 2H), 2.58-2.65
(m, 1H), 2.85 (d, 1H,
J = 15.6 Hz), 3.08-3.17 (m, 1H), 3.59 (dd, 1H,
J = 4.5, 15.7 Hz), 4.49 (s, 2H), 6.01 (d, 1H,
J = 4.5 Hz), 6.48 (dd, 1H,
J = 1.8, 9.1 Hz), 7.01 (d, 1H,
J = 1.5 Hz), 7.05 (d, 1H,
J = 8.4 Hz), 7.17 (d, 1H,
J = 2.7 Hz), 10.60 (s, 1H); ESI-MS (m/z, %) 254 (MH
+, 62), 185 (100). A solution of the amine (0.053 g, 0.209 mmol) in dry ethanol (3
mL) was treated with thiophene-2-carboximidothioic acid methyl ester hydroiodide (0.12
g, 0.418 mmol) at room temperature and the solution was stirred for 24 h. Solvent
was evaporated, crude was diluted with sat. NaHCO
3 solution (20 mL) and product was extracted into CH
2Cl
2 (2 × 20 mL). The combined CH
2Cl
2 layer was washed with brine (15 mL) and dried (Na
2SO
4). Solvent was evaporated and crude was purified by column chromatography (2 M NH
3 in MeOH: CH
2Cl
2, 5:95) to obtain compound
142 (0.06 g, 79%) as a solid. mp 122-124 °C;
1H NMR (DMSO
-d6) δ 1.38-1.46 (m, 1H), 1.70-1.78 (m, 2H), 1.93-2.12 (m, 2H), 2.20-2.28 (m, 2H), 2.62-2.72
(m, 1H), 2.83 (d, 1H,
J =15.9 Hz), 3.07-3.13 (m, 1H), 3.59 (dd, 1H,
J = 4.5, 16.0 Hz), 6.07 (d, 1H,
J = 3.9 Hz), 6.22 (brs, 2H), 6.66 (d, 1H,
J = 8.1 Hz), 7.09 (dd, 1H,
J = 3.9, 4.9 Hz), 7.22 (s, 1H), 7.30-7.32 (m, 2H), 7.58 (d, 1H,
J = 4.5 Hz), 7.71 (d, 1H,
J = 2.7 Hz), 10.92 (s, 1H); ESI-MS (m/z, %) 363 (MH
+, 20), 294 (100), 182 (15); ESI-HRMS calculated for C
21H
23N
4S (MH
+), calculated: 363.1655; observed: 363.1637.
Example 39. (R)-N-(3-(2-(1-Methylpyrrolidin-2-yl)ethyl)-1H-indol-5-yl)thiophene-2-carboximidamide (147):
[0324]
[0325] Preparation of 5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indole (92): See Example 26 for experimental details.
Preparation of (S)-benzyl 2-(2-chloro-2-oxoethyl)pyrrolidine-1-carboxylate (143):
[0326]
- i) Formation of (S)-2-(1-(benzyloxycarbonyl)pyrrolidin-2-yl)acetic acid: To a reaction vial fitted with a magnetic stirbar was added L-B-Homoproline hydrochloride
(250 mg, 1.51 mmol) as an off-white solid. The vessel was closed with a septum and
cap, and placed in an ice-water bath. 2 N Sodium hydroxide solution (1.45 mL) was
added, and the salt dissolved to give a brown solution. The septum was pierced with
2 syringes, one containg benzyl chloroformate (280 µL, 1.96 mmol), the second with
1.1 mL of 2 N sodium hydroxide (2.20 mmol). A 3rd needle was added to relieve pressure. The two liquids were added alternatively, a
little at a time to attempt to maintain a constant pH. After all reagents were added,
the reaction was allowed to stir for 2 hours in the icewater bath. The reaction was
transferred to a separatory funnel and ether (5 mL) was added. The ether layer was
removed, and the aqueous acidified to a pH of 3 by the addition of 1 M aqueous HCl.
The aqueous was extracted with ethyl acetate (3 x 5mL). The combined organis were
washed with brine, dried over sodium sulfate, decanted and concentrated to afford
a yellow oil. Yield: 264 mg (66%) 1H NMR (DMSO-d6) δ 12.22 (bs, 1H), 7.35 (m, 5H), 5.07 (s, 2H), 4.05 - 4.02 (t, J = 7.2 Hz, 2H), 3.32
- 2.63 (m, 1H), 2.31- 2.28 (m, 1H), 1.99 (s, 2H), 1.90 -1.68 (m, 4H), 1.20-1.15 (t,
J = 7.2Hz, 1H).
- ii) To an argon purged round bottom flask fitted with a magnetic stirbar was added
(S)-2-(1-(benzyloxycarbonyl)pyrrolidin-2-yl)acetic acid (235 mg, 0.893 mmol) followed
by anhydrous dichloromethane (5 mL). The reaction was treated with anhydrous DMF (2
drops ∼5 µL). The flow of argon was stopped, and the reaction vessel fitted with a
balloon. Oxalyl chloride (0.12 mL, 1.38 mmol) was added in two portions, resulting
in effervescence. The reaction was stirred at room temperature for 3 hours, before
being concentrated to dryness under reduced pressure and dried overnight under high
vacuum.
[0327] Preparation of (S)-benzyl 2-(2-(5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indol-3-yl)-2-oxoethyl)pyrrolidine-1-carboxylate
(144): In a similar fashion to the synthesis of compound
94, Example 26, compound
144 was isolated as a yellow solid (240 mg, 59%).
1H NMR (CDCl
3) δ: 8.72 and 8.44 (2s, 1H), 8.26 and 8.11 (2m, 1H), 7.45 -7.39 (m, 7H), 7.44 - 7.34
(m, 4H), 7.11 - 7.09 (d, 1H, J = 7.8 Hz), 5.89 (bs, 2H), 5.19 (s, 2H), 4.36 (m, 1H),
3.49 (s, 1H), 3.50 - 3.41 (m, 2H), 2.03 (s, 6H), 2.00 - 1.90 (m, 5H), MS-ESI m/z (%):
456 (M
+, 100).
[0328] Preparation of (R)-5-(2,5-dimethyl-1H-pyrrol-1-yl)-3-(2-(1-methylpyrrolidin-2-yl)ethyl)-1H-indole
(145): To an argon purged round bottom flask fitted with a magnetic stirbar and containing
a solution
144 (210 mg, 0.461 mmol) in anhydrous THF (5 mL) was added lithium aluminum hydride (79
mg, 2.08 mmol). The flask was fitted with a condenser and placed in an oil bath. The
reaction was heated to 75°C and stirred at reflux with an argon flow for 4.5 hrs.
The reaction was revealed to be complete by TLC (10% 2M NH
3 in MeOH, 90% CH
2Cl
2) and was cooled gradually to room temperature. The reaction was quenched by the addition
of water (0.2 mL), 3N sodium hydroxide (0.3 mL) and water (0.6 mL). The react was
filtered through celite and partitioned with ethyl acetate (10 mL). The aqueous layer
was extracted twice more with ethyl acetate (2 x 10 mL). The combined organics were
washed with brine, dried over sodium sulfate and concentrated after decanting to afford
a brown oil. The product was purified by silica gel column chromatography (1:1 Ethyl
acetate/Hexanes to 5% 2M NH
3 in MeOH, 95% CH
2Cl
2) to afford the desired product as a yellow oil, compound 145. Yield: 105 mg (71%).
1H NMR (CDCl
3) δ 8.09 (bs, 1H), 7.44 - 7.43 (d, 1H, J = 1.5 Hz), 7.41- 7.38 (d, 1H, 8.7 Hz), 7.08
(d, 1H, J = 2.1 Hz), 7.03 - 7.00 (dd, 1H, J = 1.8, 8.1 Hz), 5.91 (bs, 2H), 3.49 (s,
1H), 3.15 - 3.10 (m, 2H), 2.86 - 2.65 (m, 3H), 2.34 (s, 4H), 2.03 (bs, 6H), 1.90 -1.52
(m, 4H). MS-ESI (m/z, %) 322 (M
+, 100)
[0329] Preparation of (R)-3-(2-(1-methylpyrrolidin-2-yl)ethyl)-1H-indol-5-amine (146): To an argon purged round bottom flask fitted with a magnetic stirbar and containing
a yellow solution of
145 (94 g, 0.292 mmol) in anhydrous 2-propanol (6 mL) and water (2 mL) was added solid
hydroxylamine hydrochloride (406 mg, 5.84 mmol) in one portion. Triethylamine (407
µL, 2.92 mmol) was added via syringe and the flask was fitted with a condensor. The
vessel was placed in an oil bath and heated to reflux. The reaction was stirred at
reflux under argon for 6 hours. TLC (10% 2M NH
3 in MeOH, 90% CH
2Cl
2) revealed the reaction was complete, and so the reaction was cooled to room temperature.
Sodium hydroxide pellets (120 mg, 3.0 mmol) were added slowly. The reaction was stirred
vigourously overnight. The reaction was filtered through celite, followed by washing
of the celite with 2-propanol (40 mL) and absorption of the filtrate onto silica gel.
The product was purified by column chromatography (5-10% 2M NH
3 in MeOH, 90% CH
2Cl
2) using a silica gel plug approximately 15 mm in diameter by 30 mm in height to afford
an orange solid. This product was partitioned between brine (5 mL) and ethyl acetate
(10 mL). The organic was dried with anhydrous sodium sulfate before being decanted.
Concentration afforded an orange oil, compound
146. Yield: 48 mg of orange oil (68%)
1H NMR (DMSO-
d6) δ 10.19 (s, 1H), 7.02 - 6.99 (d, J = 5.4 Hz, 1H), 6.90 - 6.89 (d, J = 2.1 Hz, 1H),
6.64 - 6.63 (d, J = 1.5 Hz, 1H), 6.47 - 6.43 (dd, J = 1.8, 8.7 Hz, 1H), 4.42 (bs,
1H), 2.97 - 2.90 (m, 1H), 2.59 (m, 2H), 2.20 (s, 3H), 2.05 - 1.97 (m, 4H), 1.69 -
1.40 (m, 4H).
Preparation of (R)-N-(3-(2-(1-methylpyrrolidin-2-yl)ethyl)-1H-indol-5-yl)thiophene-2-carbozimidamide
dihydrochloride (147):
[0330] To an argon purged round bottom flask was charged
146 (40 mg, 0.164 mmol) and thiophene-2-carboximidothioic acid methyl ester hydroiodide
(94 mg, 0.329 mmol) followed by absolute ethanol (3 mL). The reaction was stirred
using a magnetic stirbar for 60 hours at room temperature. TLC (10% 2 M ammonia in
methanol/90% dichloromethane) revealed all starting amine had reacted. The reaction
as treated with ether (50 mL). The resulting yellow precipitate was collected by vacuum
filtration and washed with ether. The precipitate was washed from the filter using
methanol. The residue was concentrated, and purified by silica gel column chromatography
(5-10% 2M ammonia in methanol/95-90% dichloromethane) to afford a yellow oil. The
purified product was dissolved in anhydrous methanol (3 mL) and treated with 1M hydrogen
chloride in ether (5 mL). After stirring for 30 minutes the precipitate was collected
by vacuum filtration. The precipitate was washed with ether, followed by washing from
the filter with methanol. The filtrate was concentrated and dried under high vacuum.
Yield: 21 mg of yellow solid, compound
147 (30%) Melting point 212 °C. 1H NMR (MeOD
-d3) δ 8.09 (br s, 2H), 7.76 (s, 1H), 7.59 (d, 1H, J = 8.7 Hz), 7.41 (br s, 1H), 7.35
(s, 1H), 7.19 (d, 1H, J = 8.7 Hz), 3.67 (br m, 1H), 3.19 (br m, 1H), 3.1-2.8 (br m,
2H), 2.91 (s, 3H), 2.46 (br m, 2H), 2.2-1.8 (br m, 5H). MS (TOF+): Exact calc. for
C
20H
25N
4S 353.1794 (MH
+), found 353.1782.
Example 40. Preparation of N-[1-(3-morpholin-4-yl-propyl)-1H-indol-6-yl]-thiophene-2-carboxamidine
Hydrochloride (151)
[0331]
[0332] 1-(3-Chloropropyl)-6-nitro-1H-indole (148): Sodium hydride (1.96 g, 49.337 mmol, 60% suspension in mineral oil) was treated with
DMF (60 mL), followed by 6-nitroindole
(6) (2.0 g, 12.334 mmol) in DMF (20 mL) over a period of 5 min at 0 °C. After stirring
for 15 min, the solution was treated with 1-chloro-3-iodopropane (3.9 mL, 37.002 mmol),
the reaction was brought to room temperature and stirred for 3 h. The reaction was
quenched with saturated brine (80 mL), water (80 mL) and cooled to 0 °C. The solid
was filtered off, washed with water (50-75 mL) and dried to obtain the crude product
The crude product was recrystallised from hot toluene (10 mL) / hexanes (5 mL) to
obtain compound
148 (2.637 g, 90%) as solid. mp 85-87 °C;
1H-NMR (CDCl
3) δ 2.28-2.36 (m, 2H), 3.46 (t, 2H,
J= 5.7 Hz), 4.45 (t, 2H,
J= 6.6 Hz), 6.62 (d, 1H,
J= 2.7 Hz), 7.43 (d, 1H,
J= 3.0 Hz), 7.66 (d, 1H,
J= 8.7 Hz), 8.02 (dd, 1H,
J= 1.8, 7.9 Hz), 8.36 (d, 1H,
J= 0.9 Hz).
[0333] 1-(3-Morpholin-4-yl-propyl)-6-nitro-1H-indole (149): A solution of compound
148 (2.35 g, 9.845 mmol) in dry CH
3CN (40 mL) was treated with K
2CO
3 (13.6 g, 98.458 mmol), KI (16.3 g, 98.458 mmol) and morpholine (8.58 mL, 98.458 mmol)
at room temperature. The resulting mixture was refluxed for overnight (15 h). The
reaction was brought to room temperature and the solvent was evaporated. The mixture
was diluted with water (100 mL) and extracted with ethyl acetate (2 × 50 mL). The
combined ethyl acetate layer was washed with water (25 mL), brine (20 mL) and dried
(Na
2SO
4). The solvent was evaporated under reduced pressure and the crude product was purified
by column chromatography (EtOAC: 2M NH
3 in methanol/CH
2Cl
2, 1:1) to obtain compound
149 (2.85 g, quantitative) as a syrup.
1H-NMR (CDCl
3) δ 1.97-2.06 (m, 2H), 2.23 (t, 2H,
J= 6.3 Hz), 2.38 (brs, 4H), 3.75 (t, 4H,
J= 4.5 Hz), 4.33 (t, 2H,
J= 6.6 Hz), 6.59 (d, 1H,
J= 3.0 Hz), 7.39 (d, 1H,
J= 3.0 Hz), 7.64 (d, 1H,
J= 8.7 Hz), 8.00 (dd, 1H,
J= 1.8, 8.7 Hz), 8.42 (brs, 1H).
[0334] N-[1-(3-Morpholin-4-yl-propyl)-1H-indol-6-yl]-thiophene-2-carboxamidine (150): A solution of compound
149 (2.0 g, 6.912 mmol) in abs. ethanol (20 mL) was treated with Pd-C (0.25 g), purged
with hydrogen gas and stirred for overnight (15 h) under hydrogen atm. (balloon pressure).
The reaction mixture was filtered through a celite pad and washed with abs. ethanol
(2 × 20 mL). The combined ethanol layer was treated with thiophene-2-carboximidothioic
acid methyl ester hydroiodide (3.94 g, 13.824 mmol) and the resulting mixture was
stirred for overnight (16 h) at room temperature. The solvent was evaporated and the
product was precipitated with ether (250 mL). The solid was dissolved into sat NaHCO
3 sol.: CH
2Cl
2 (100 mL, 1:1). The org. layer was separated and aqueous layer was extracted with
CH
2Cl
2 (2 × 50 mL). The combined CH
2Cl
2 layer was washed with brine (25 mL) and dried (Na
2SO
4). The solvent was evaporated and the crude product was purified by column chromatography
(2M NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
150 (2.348 g, 92%) as a foam.
1H-NMR (DMSO
-d6) δ 1.83-1.91 (m, 2H), 2.19 (t, 2H,
J = 6.6 Hz), 2.30 (brs, 4H), 3.56 (t, 4H,
J = 4.8 Hz), 4.14 (t, 2H,
J = 6.6 Hz), 6.34-6.35 (m, 3H), 6.58 (dd, 1H,
J = 1.2, 8.2 Hz), 6.95 (brs, 1H), 7.09 (dd, 1H,
J = 3.9, 5.1 Hz), 7.21 (d, 1H,
J = 3.0 Hz), 7.44 (d, 1H,
J = 8.1 Hz), 7.59 (d, 1H,
J = 3.9 Hz), 7.72 (dd, 1H,
J = 0.9, 3.6 Hz).
[0335] Hydrochloride salt of N-[1-(3-morpbolin-4-yl-propyl)-1H-indol-6-yl]-thiophene-2-carboxamidine
(151): A solution of compound
150 (0.65 g, 1.763 mmol) in methanol (5 mL) was treated with 1 N HCl in ether (5.3 mL,
5.291 mmol) at 0 °C. The reaction was brought to room temperature and stirred for
30 min. The solvent was evaporated and the crude product was recrystallized from ethanol/ether
to obtain compound
151 (0.66 g, 85%) as a solid. mp 100-105 °C. ESI-MS m/z (%): 369 (M
+, 100).
Example 41. Preparation of N-(1-(3-(diethylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide dihydrochloride_(153)
[0336]
[0337] Preparation of 1-(3-chloropropyl)-6-nitro-1H-indole (148): Procedure described in Example 40. (Yield: 796.6 mg, greater than 100%)
Preparation of N,N-diethyl-3-(6-nitro-1H-indol-1-yl)propan-1-amine (152):
[0338] Reaction performed as described in Example 40, using diethylamine as nucleophile.
Product purified using silica gel column chromatography (2.5 - 5% 2M ammonia in methanol,
97.5 - 95% dichloromethane). Yield: 145.1 mg of compound
152 as a dark yellow oil (83.9%).
1H-NMR (CDCl
3) δ 8.37 (s, 1H), 8.02 - 7.99 (dd, J = 2.1, 9 Hz, 1H), 7.66 -7.63 (d, J = 8.7 Hz,
1H), 7.43 - 7.42 (d, J = 3 Hz, 1H), 6.60 - 6.58 (d, J = 3Hz, 1H), 4.32 - 4.27 (t,
J = 6.9 Hz, 2H), 2.57 - 2.50 (q, J = 7.1 Hz, 4H), 2.43 - 2.39 (t, J = 6.6 Hz, 2H),
2.07 -1.98 (quintet, J = 6.6 Hz, 2H), 1.03 - 0.99 (t, J = 6.9 Hz, 6H).
[0339] Preparation of Amberlite ion exchange resin used for the formation of freebase: To a 100 mL coarse buchner funnel was added Amberlite IRA-900 ion-exchange resin
(15.25 g, approx 15 mmol) suspended in water (50 mL). The funnel was placed under
vacuum to pack the solid. The solid was washed with water (50 mL) and the solvent
removed through vacuum filtration. A solution of 10% sodium hydroxide (12.5 g, in
100 mL) was prepared and added to the resin in 25 mL portions. The resin was stirred
with a glass stirring rod for 30 s after the addition of each portion before being
put under vacuum. After the 4 basic washes, the resin was washed with water in 50
mL portions until the pH was neutral by pH paper (approx 400 mL water). The resin
was dried under vacuum for 2 minutes. Denatured ethanol (2x50 mL) was used to wash
the resin with stirring, followed by absolute ethanol (3 x 50 ML). The final product
was dried under high vacuum for 15 minutes. Yield: 12.95 g of yellow beads.
[0340] Preparation of N-(1-(3-(diethylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide dihydrochloride
(153): Reaction performed as described in Example 40, compound
150. Following isolation of the HI salt by precipitation, the salt was dissolved in ethanol.
Amberlite resin (3.00 g) was added to the solution, and the mixture stirred at room
temperature for 30 minutes. The reaction was diluted with ethyl acetate (30 mL) and
filtered. The filtrate was concentrated to afford a yellow oil. The material was absorbed
onto silica gel and purified by silica gel column chromatography (5% 2M ammonia in
methanol, 95% dichloromethane). The resulting yellow oil was found to be the desired
product, compound
152, by
1H-NMR analysis. The oil was dissolved in anhydrous dichloromethane (5 mL) and transferred
to an argon purged reaction vial. The solution was treated with 1M hydrochloric acid
in ether (3 mL) and the salt oiled out immediately. The reaction was stirred for 10
minutes and filtered. The vial and the filter were washed with ethyl acetate and the
filtrate discarded. The yellow-brown oil which remained in the reaction vial was dissolved
in methanol and the solution poured through the filter. The filter was washed with
methanol and all organics combined and concentrated to afford a yellow oil. Additional
drying under high vacuum afforded a yellow oil, compound 153. Yield: 80.1 mg of yellow
oil.
1H-NMR (DMSO
-d6) δ 7.74 - 7.73 (d, J = 3.3 Hz, 1H), 7.61- 7.60 (d, J = 4.5, 1H), 7.47 -7.44 (d, J
= 8.1 Hz, 1H), 7.27 (s, NH), 7.22 - 7.21 (d, J = 3 Hz, 1H), 7.11-7.08 (t, J=4.8Hz,
1H), 6.92 (s, 1H), 6.60 - 6.57 (dd, J = 1.2, 8.4 Hz, 1H), 6.34 - 6.33 (d, J = 3 Hz,
2H), 4.16 - 4.12 (t, J = 6.9 Hz, 2H), 2.46 (s, 4H), 2.36 - 2.31 (t, J = 6.6 Hz, 2H),
1.93-1.83 (quintet, J = 6.7 Hz, 2H), 1.67 (s, 4H) MW 353.
Examples 42. Preparation of N-(1-(3-(pyrrolidin-1-yl)propyl-1H-indol-6-yl)thiophene-2-carboximidamide
dihydrochloride (155)
[0341]
[0342] Preparation of 1-(3-chloropropyl)-6-nitro-1H-indole (148): Procedure described under Example 40. (Yield: 796.6 mg, greater than 100%)
[0343] Preparation of 1-(3-chloropropyl)-6-nitro-1H-indole (154): Reaction performed as described in Example 40, using pyrrolidine as nucleophile.
The product was purified using silica gel column chromatography (2.5 - 5% 2M ammonia
in methanol, 97.5 - 95% dichloromethane). Yield: 148.1 mg of compound
154 as a dark yellow oil (86.3%).
1H-NMR (CDCl
3) δ 8.43 (s, 1H), 8.02 - 7.98 (dd, J = 2.1, 9 Hz, 1H), 7.66 -7.63 (d, J = 8.7 Hz,
1H), 7.43 - 7.42 (d, J = 3 Hz, 1H), 6.60 - 6.59 (d, J = 3.3 Hz, 1H), 4.36 - 4.31 (t,
J = 6.9 Hz, 2H), 2.49 (bs, 4H), 2.41 - 2.37 (t, J = 6.6 Hz, 2H), 2.10 - 2.01 (quintet,
J = 6.7 Hz, 2H), 1.85 -1.81 (m, 4H)
[0344] Preparation of N-(1-(3-(pyrrolidin-1-yl)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide
dihydrochloride (155): Reaction performed as described in Example 40, compound
150. Following isolation of the HI salt by precipitation (193.5 mg), the salt was dissolved
in ethanol. Treated amberlite resin (3.00 g) was added to the solution, and the mixture
stirred at room temperature for 30 minutes. The reaction was diluted with ethyl acetate
(30 mL) and filtered. The filtrate was concentrated to afford a yellow oil. The material
was absorbed onto silica gel and purified by silica gel column chromatography (5 -
10% 2M ammonia in methanol, 95 - 90% dichloromethane). The resulting yellow oil was
found to be the desired product, compound
154, by
1H-NMR The oil was dissolved in anhydrous dichloromethane (5 mL) and transferred to
an argon purged reaction vial. The solution was treated with 1M hydrochloric acid
in ether (3 mL) and the salt oiled out immediately. The reaction was stirred for 10
minutes and filtered. The vial and the filter were washed with ethyl acetate and the
filtrate discarded. The yellow-brown oil which remained in the reaction vial was dissolved
in methanol and the solution poured through the filter. The filter was washed with
methanol and all organics combined and concentrated to afford a yellow oil. Additional
drying under high vacuum afforded a yellow solid, compound
155. Yield: 116 mg of yellow solid.
1H-NMR (DMSO-
d6) δ 7.73 - 7.72 (d, J = 3.6 Hz, 1H), 7.60 - 7.59 (d, J = 4.5, 1H), 7.46 -7.43 (d,
J = 8.1 Hz, 1H), 7.21-7.20 (d, J = 3 Hz, 1H), 7.11-7.08 (t, J=4.8Hz, 1H), 6.92 (s,
1H), 6.60 - 6.57 (dd, J = 1.2, 8.4 Hz, 1H), 6.34 - 6.33 (d, J = 3 Hz, 2H), 4.16 -
4.12 (t, J = 6.9 Hz, 2H), 2.46 (s, 4H), 2.36 - 2.31 1 (t, J = 6.6 Hz, 2H), 1.93-1.83
(quintet, J = 6.7 Hz, 2H), 1.67 (s, 4H). MW 353.
Example 43. Preparation of N-(1-(3-(dimethylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide
dihydrochloride (157)
[0345]
[0346] Preparation of 1-(3-chloropropyl)-6-nitro-1H-indole (148): Procedure described under Example 40. (Yield: 796.6 mg, greater than 100%)
Preparation of N,N-dimethyl-3-(6-nitro-1H-indol-1-yl)propan-1-amine (156):
[0347] Reaction performed as described in Example 40, using dimethylamine as nucleophile.
The product was purified using silica gel column chromatography (2.5-5% 2M ammonia
in methanol, 97.5 - 95% dichloromethane). Yield: 121.4 mg of compound
156 as a dark yellow oil (88.3%).
1H-NMR (CDCl
3) δ 8.41-8.40 (d, J =1.8 Hz, 1H), 8.02 - 7.99 (dd, J = 2.1, 9 Hz, 1H), 7.66 -7.63
(d, J = 8.7 Hz, 1H), 7.43-7.42 (d, J = 3 Hz, 1H), 6.60 - 6.59 (d, J = 3.3 Hz, 1H),
4.33 - 4.29 (t, J = 6.9 Hz, 2H), 2.23 - 2.19 (m, 8H), 2.43 (s, 3H), 2.05-1.96 (quintet,
J = 6.7 Hz, 2H).
[0348] Preparation of N-(1-(3-(dimethylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide
dihydrochloride (157): Reaction performed as described in Example 40, compound
150. Following isolation of the HI salt by precipitation (186.6 mg), the salt was dissolved
in ethanol. Treated amberlite resin (3.00 g) was added to the solution, and the mixture
stirred at room temperature for 30 minutes. The reaction was diluted with ethyl acetate
(30 mL) and filtered. The filtrate was concentrated to afford a yellow oil. The material
was absorbed onto silica gel and purified by silica gel column chromatography (5-10%
2M ammonia in methanol, 95 - 90% dichloromethane). The hydrochloride salt was formed
using the procedure described for Example 40, compound
151. Yield: 61.7 mg of compound
157 as a yellow-orange solid.
1H-NMR (DMSO-
d6) δ 7.74-7.73 (d, J = 3.9 Hz, 1H), 7.61-7.59 (d, J = 4.5Hz, 1H), 7.46 -7.43 (d, J
= 8.1 Hz, 1H), 7.21 - 7.20 (d, J = 3 Hz, 1H), 7.11-7.09 (t, J=4.8Hz, 1H), 6.91 (s,
1H), 6.60 - 6.58 (d, J = 8.1 Hz, 1H), 6.35 - 6.34 (d, J = 3 Hz, 3H), 4.14 - 4.10 (t,
J = 6.9 Hz, 2H), 2.19 - 2.15 (t, J = 6.6 Hz, 2H), 2.12 (s, 6H), 1.89-1.80 (quintet,
J = 6.7 Hz, 2H), 1.75 (s, 2H). ESI-MS m/z (%): 327 (M
+, 100).
Example 44. Preparation of N-(1-(3-(methylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide dihydrochloride
(159)
[0349]
[0350] Preparation of
1-(3-chloropropyl)-6-nitro-1H-indole (148): Procedure described under Example 40. (Yield: 796.6 mg, greater than 100%)
Preparation of N-methyl-3-(6-nitro-1H-indol-1-yl)propan-1-amine (158):
[0351] Reaction performed as described in Example 40, using methylamine as nucleophile.
The product was purified using silica gel column chromatography (2.5-5% 2M ammonia
in methanol, 97.5 - 95% dichloromethane). Yield: 91.7 mg of compound
158 as a dark yellow oil (94.1%).
1H-NMR (CDCl
3) δ 8.40- 8.39 (d, J = 1.8 Hz, 1H), 8.02-7.99 (dd, J = 2.1, 9 Hz, 1H), 7.66 -7.63
(d, J = 8.7 Hz, 1H), 7.42 - 7.41 (d, J = 3 Hz, 1H), 6.60 - 6.59 (d, J = 3.3 Hz, 1H),
4.36 - 4.31 (t, J = 6.9 Hz, 2H), 2.59 - 2.54 (t, J = 6.6 Hz, 2H), 2.43 (s, 3H), 2.07-1.98
(quintet, J =6.7Hz,2H)
[0352] Preparation of N-(1-(3-(methylamino)propyl)-1H-indol-6-yl)thiophene-2-carboximidamide dihydrochloride
(159): Reaction performed as described in Example 40, compound
150. Following isolation of the HI salt by precipitation (121.9 mg), the salt was dissolved
in ethanol. Treated amberlite resin (3.00 g) was added to the solution, and the mixture
stirred at room temperature for 35 minutes. The reaction was diluted with ethyl acetate
(15 mL) and filtered. The filtrate was concentrated to afford a yellow oil. The material
was absorbed onto silica gel and purified by silica gel column chromatography (5 -
10% 2M ammonia in methanol, 95 - 90% dichloromethane). Reaction converted to hydrochloride
salt using procedure described in Example 40 for compound
151. Yield: 87.2 mg of compound
159 as a yellow-orange solid.
1H-NNM (DMSO-
d6) δ 7.74-7.73 (d, J = 3.6 Hz, 1H), 7.61-7.59 (d, J = 4.5,1H), 7.46 -7.43 (d, J = 8.1
Hz, 1H), 7.21 - 7.20 (d, J = 3 Hz, 1H), 7.11-7.09 (t, J=4.8Hz, 1H), 6.92 (s, 1H0),
6.60 - 6.57 (dd, J = 1.2, 8.4 Hz, 1H), 6.34 - 6.33 (d, J = 3 Hz, 2H), 4.17 - 4.12
(t, J = 6.9 Hz, 2H), 2.46 - 2.41 (t, J = 6.6 Hz, 2H), 2.25 (s, 3H), 1.87-1.83 (quintet,
J = 6.7 Hz, 2H). ESI-MS m/z (.%): 327 (M
+, 100).
Example 45. Preparation of N-(2-benzyl-1-(2-(1-methylpyrrolidin-2-yl)ethyl)-1H-indol-6-yl)thiophene-2-carboximidamide
(164)
[0353]
[0354] Preparation of compound 160: 6-nitroindole (
6) (1.0 g, 6.167 mmol) was subjected to conditions as per
Organic Syntheses, Coll. Vol. 6, p 104 and the crude product slurried in boiling hexanes, filtered and dried to yield compound
160.
1H-NMR (CDCl
3) δ 8.29 (m, 1H), 8.02 (dd, 1H, J=1.9, 8.8), 7.68 (d, 1H, J=8.5), 7.41 (d, 1H, J=3.1),
7.31 (m, 3H), 7.13, (m, 2H), 6.65 (d, 1H, J=3.0), 5.40 (s, 2H). MS (ESI+): 253 (M+1,
100%).
[0355] Preparation of compound 161: A solution of 1-benzyl-6-nitro-1H-indole (compound
160, 0.5 g, 1.982 mmol) was treated with Polyphosphoric Acid as per
Synthetic Communications, 27(12), 2033-2039 (1997) and the crude product purified via silica gel column chromatography (2:8 ethyl acetate:
hexanes) to provide compound
161 (115 mg, 23.0%);
1H-NMR (CDCl
3) δ 8.25-8.10 (2 x , 2H), 7.99 (dd, 1H, J=2.1,8.9), 7.56 (d, 1H, J=8.7), 7.45-7.12
(m, 5H), 6.44 (d, 1H, J=1.6), 4.19 (s, 2H). MS (ESI+): 253 (M+1, 100%).
[0356] Preparation of compound 162: 2-benzyl-6-nitro-1H-indole (compound
161, 110 mg, 0.436 mmol), 2-(2-chloroethyl)-1-methylpyrrolidine hydrochloride (88.3 mg,
0.479 mmol), and powdered potassium carbonate (180.8 mg, 1.308 mmol) were placed in
an argon-purged flask. DMF (5 mL, Aldrich sure seal™) was added and the mixture heated
to 65 °C in an oil bath for 20 hours. The solution was cooled to room temperature
and diluted with water (10 mL) and ethyl acetate (25 mL). The layers were separated
and the aqueous phase extracted with ethyl acetate (2 x 25 mL). The organic extracts
were combined, washed with brine (2 x 10 mL) and dried over magnesium sulfate. The
sample was filtered, concentrated, and the resultant crude product purified using
dry silica gel column chromatography eluting with 10-15 mL portions of solvent system
(2.5% 2M NH
3 in methanol/95% dichloromethane) to afford a yellow residue
162 (47 mg, 29.7% yield);
1H-NMR (CDCl
3) δ 8.25 (s, 1H), 8.00 (dd, 1H, J = 1.9, 8.8), 7.55 (d, 1H, J = 8.7), 7.37-7.17 (m,
5H), 6.36 (s, 1H), 4.19 (d, 2H, J = 3.4), 4.12 (m, 2H), 3.12 (m, 1H), 2.26 (s, 3H),
2.20 (m, 1H), 2.01-1.85 (m, 2H), 1.84-1.66 (m, 2H), 1.63-1.40 (m, 3H); MS (ESI+):
274.5 (M+1, 100%).
[0357] Preparation of compound 164: 2-benzyl-1-(2-(1-methylpyrrolidin-2-yl)ethyl)-6-nitro-1H-indole (compound
162, 40 mg, 0.110 mmol) was dissolved in anhydrous ethanol (5 mL) in a dry argon purged
flask. Palladium, 10wt% on activated carbon (11.7 mg, 0.011 mmol) is quickly added
and the atmosphere from the flask evacuated by vacuum pump and replaced with hydrogen
from a balloon. The atmosphere is evacuated from the flask and replaced with hydrogen
twice more and the mixture stirred under a hydrogen atmosphere at room temperature.
After 3 hours, thin layer chromatography in a solvent system of (5% 2M NH
3 in methanol/95% dichloromethane) shows complete conversion to compound
163, 2-benzyl-1-(2-(1-methylpyrrolidin-2-yl)ethyl)-1H-indol-6-amine, which is utilized
without isolation. The mixture is filtered through a pad of celite to remove insolubles,
the pad washed with anhydrous ethanol (5 mL) and the ethanolic solution of the amine
163 is charged to a small, argon purged flask fitted with a magnetic stirbar. Thiophene-2-carboximidothioic
acid methyl ester hydroiodide (40.8 mg, 0.143 mmol) is added to the flask and the
reaction was stirred under Ar at ambient temperature for 48 hours. An additional amount
of the thiophene-2-carboximidothioic acid methyl ester hydroiodide (0.3 eq) was added
and stirring continued for an additional 18 hours. A further portion of thiophene-2-carboximidothioic
acid methyl ester hydroiodide (0.3 eq) was added and stirring continued for an additional
18 hours, at which time the mixture was concentrated and the residue purified via
chromatography on silica gel (2.5% 2M NH
3 in methanol/ 97.5% dichloromethane to 5% 2M NH
3 in methanol/ 95% dichloromethane) to afford yellow oil, compound
164 (38 mg, 78.0% yield);
1H-NMR (CDCl
3) δ 7.72 (d, 1H, J=3.2), 7.59 (d, 1H, J=4.7), 7.38 (d, 1H, J=8.1), 7.35-7.20 (m, 5H),
7.09 (m, 1H), 6.77 (s, 1H), 6.56 (d, 1H, J=7.4), 6.36 (br s, 2H), 6.14 (s, 1H), 4.14
(s, 2H), 3.96 (t, 2H, J=7.9), 2.94-2.86 (m, 1H), 2.09 (s, 3H), 2.06-1.94 (m, 2H),
1.89-1.78 (m, 1H), 1.69-1.51 (m, 3H), 1.45-1.35 (m, 2H); MS (ESI+): 443 (M+1, 70%),
219 (100%).
Example 46. Preparation of N-(1-(4-(1H-imidazol-1-yl)butyl)-1H-indol-6-yl)thiophene-2-carboximidamide
(168)
[0358]
[0359] Preparation of compound 165: To sodium hydride (0.987 g, 24.68 mmol) in a 100 mL argon-purged flask fitted with
a stir bar and an Argon atmosphere was added anhydrous DMF (10 mL) and the mixture
was cooled to 0 °C in an ice bath. A solution of 6-nibroindole (
6) (1.00 g, 6.17 mmol) in DMF (10 mL) was added slowly to the NaH mixture and after
addition was complete the ice bath was removed and the reaction stirred at room temperature
for ~ 5min. In a second oven dried argon purged flask fitted with a stir bar was charged
1-Chloro-4-iodo-butane (2.26 mL, 18.51 mmol) and DMF (10 mL). The indole solution
was added via cannula to the chlorobutane solution over a period of 10 min and the
mixture was stirred at RT. After 20 min, the reaction was placed in an ice bath and
quenched with brine (10 mL). The reaction was diluted with ethyl acetate and water
and transferred to a separatory funnel. The organic layer was separated and the aqueous
layer further extracted with EtOAc. The combined organics were washed with brine,
dried with magnesium sulfate, filtered and concentrated to afford a brown oil. The
crude product was purified via chromatography on silica gel (20% Ethyl acetate/80%
Hexanes) to afford compound
165 (1.52 g, 97.6% yield);
1H-NMR (DMSO-
d6) δ 8.57 (d, 1H, J=1.8), 7.93-7.88 (m, 1H), 7.84 (d, 1H, J = 3.0), 7.75-7.72 (m, 1H),
6.67 (d, 1H, J = 3.0), 4.39 (t, 2H, J = 7.0), 3.66 (t, 2H, J = 6.6), 1.95-1.82 (m,
2H), 1.73-1.64 (m, 2H); MS (ESI+): 253 (M+1, 100%).
[0360] Preparation of compound 166: To an over dried, Argon purged 50 mL flask fitted with stir bar and condenser, 1H-Imidazole
(0.673 g, 9.893 mmol), potassium iodide (1.642 g, 9.893 mmol) and potassium carbonate
(1.367 g, 9.893 mmol) were added as solids. 1-(4-chlorobutyl)-6-nitro-1H-indole (compound
165, 0.250g, 0.989 mmol) in a solution of acetonitrile (5 mL) was charged to the flask
and stirring began. Mixture was heated at 50°C for 16 hours then heated to reflux
for 4 hours. The reaction was cooled to room temperature and diluted with dichloromethane
(10 mL) and filtered through a pad of celite. The pad was washed further with dichloromethane
and the solution was concentrated to afford a crude yellow solid. The product was
purified by silica gel column chromatography using a solvent system of (5% 2M NH
3 in methanol/ 95% dichloromethane) to yield a yellow residue, compound
166 (182 mg, 64.7% yield);
1H-NMR (DMSO-
d6) δ 8.54 (d, 1H, J= 1.5), 7.94-7.88 (m, 1H), 7.81 (d, 1H, J = 3.0), 7.74-7.72 (m,
1H), 7.59 (s, 1H), 7.12 (s, 1H), 6.86 (s,1H), 6.66 (d, 1H, J = 3.0), 4.35 (t, 2H,
J = 6.4), 3.97 (t, 2H, J = 6.4), 1.76-1.61 (m, 4H); MS (ESI+): 307 (M + Na, 100%).
[0361] Preparation of compound 168: 1-(4-(1H-imidazol-1-yl)butyl)-6-nitro-1H-indole (compound
166, 145 mg, 0.510 mmol) was dissolved in anhydrous ethanol (7 mL) in a dry argon purged
flask. Palladium, 10wt% on activated carbon (54.2 mg, 0.051 mmol) is quickly added
and the atmosphere from the flask evacuated by vacuum pump and replaced with hydrogen
from a balloon. The atmosphere is evacuated from the flask and replaced with hydrogen
twice more and the mixture stirred under a hydrogen atmosphere at room temperature.
After 3 hours, thin layer chromatography in a solvent system of (10% 2M NH
3 in methanol/ 90% dichloromethane) shows complete conversion to compound
167, 1-(4-(1H-imidazol-1-yl)butyl)-1H-indol-6-amine, which is utilized without isolation.
The mixture is filtered through a pad of celite to remove insolubles, the pad washed
with anhydrous ethanol (7 mL) and the ethanolic solution of the amine
167 is charged to a small, argon purged flask fitted with a magnetic stir bar. Thiophene-2-carboximidothioic
acid methyl ester hydroiodide (189.1 mg, 0.663 mmol) is added to the flask and the
reaction was stirred under Ar at ambient temperature for 20 hours, at which time the
solution was diluted with diethyl ether (100 ml) resulting in the formation of a sticky
solid which could not be isolated via filtration. As a result the product was washed
off the funnel with methanol, combined with the filtrate and solvents evaporated to
leave a crude residue. The residue was partitioned between H
2O and ethyl acetate and 3M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered, concentrated and the
residue purified via chromatography on silica gel (2.5% 2M NH
3 in methanol/ 97.5% dichloromethane) to yield yellow solid, compound
168 (101 mg, 54.5% yield);
1H-NMR (DMSO-
d6) δ 7.74 (d, 1H, J= 3.0), 7.60 (d, 1H, J = 5.2), 7.56 (s, 1H), 7.45 (d, 1H, J = 8.3),
7.21 (d, 1H, J = 3.0), 7.13-7.06 (m, 2H), 6.92 (s, 1H), 6.85 (s, 1H), 6.59 (d, 1H,
J=8.0), 6.42-6.30 (br, 2 x m, 3H), 4.17-4.06 (m, 2H), 3.99-3.92 (m, 2H), 1.75-1.58
(m, 4H); MS (ESI+): 364 (M+1, 100%).
Example 47. Preparation of N-(1-(4-(dimethylamino)butyl)-1H-indol-6-yl)thiophene-2-carbozimidamide
(171)
[0362]
[0363] Preparation of compound 165: 1-(4-chlorobutyl)-6-nitro-1H-indole: Please see Example 46 for complete experimental
details and spectral data.
[0364] Preparation of compound 169: To an oven dried, Argon purged 50mL flask fitted with stir bar and condenser, dimethylamine
hydrochloride (0.806 g, 9.893 mmol), potassium iodide (1.642 g, 9.893 mmol) and potassium
carbonate (1.367 g, 9.893 mmol) were added as solids. 1-(4-chlorobutyl)-6-nitro-1H-indole
(compound
165, 0.250g, 0.989 mmol) in a solution of acetonitrile (5 mL) was charged to the flask
and stirring began. Mixture was heated at 50°C for 16 hours. The reaction was diluted
with 3-4 mL of anhydrous acetonitrile due to loss of some solvent then heated to reflux
for 8 hours. The reaction was cooled to room temperature and stirred at room temperature
over the weekend. After a total of 88 hours the reaction was diluted with dichloromethane
(10 mL) and filtered through a pad of celite. The pad was washed further with dichloromethane
and the solution was concentrated to afford a crude yellow solid. The product was
purified by silica gel column chromatography using a solvent system of (5% 2M NH
3 in methanol/95% dichloromethane to 10% 2M NH
3 in methanol/ 90% dichloromethane) to yield 2 products, the major product as a yellow
oil, compound
169 (100 mg, 38.8% yield);
1H-NMR (DMSO-
d6) δ 8.54 (d, 1H, J= 1.5), 7.93-7.88 (m, 1H), 7.83 (d, 1H, J = 3.0), 7.74-7.71 (m,
1H), 6.66 (d, 1H, J=3.0), 4.34 (t, 2H, J = 7.1), 2.18 (t, 2H, J = 7.0), 2.06 (s, 6H),
1.78 (quintet, 2H, J =7.5), 1.36 (quintet, 2H, J = 7.5); MS (ESI+): 262 (M+1, 100%).
[0365] Preparation of compound 171: N,N-dimethyl-4-(6-nitro-1H-indol-1-yl)butan-1-amine (compound
169, 88 mg, 0.337 mmol) was dissolved in anhydrous ethanol (5 mL) in a dry argon purged
flask. Palladium, 10wt% on activated carbon (35.8 mg, 0.033 mmol) is quickly added
and the atmosphere from the flask evacuated by vacuum pump and replaced with hydrogen
from a balloon. The atmosphere is evacuated from the flask and replaced with hydrogen
twice more and the mixture stirred under a hydrogen atmosphere at room temperature.
After 3 hours, thin layer chromatography in a solvent system of (10% 2M NH
3 in methanol/ 90% dichloromethane) shows complete conversion to
170, 1-(4-(dimethylamino)butyl)-1H-indol-6-amine, which is utilized without isolation.
The mixture is filtered through a pad of celite to remove insolubles, the pad washed
with anhydrous ethanol (5 mL) and the ethanolic solution of the amine
170 is charged to a small, argon purged flask fitted with a magnetic stir bar. Thiophene-2-carboximidothioic
acid methyl ester hydroiodide (124.9 mg, 0.438 mmol) is added to the flask and the
reaction was stirred under Ar at ambient temperature for 20 hours, at which time the
solution was diluted with diethyl ether (100 ml) resulting in the formation of a sticky
solid which could not be isolated via filtration. As a result the product was washed
off the funnel with methanol, combined with the filtrate and solvents evaporated to
leave a crude residue. The residue was partitioned between H
2O and ethyl acetate and 3M sodium hydroxide solution added to adjust pH to 9. The
mixture was transferred to a separatory funnel and the organic layer collected. The
aqueous layer was further extracted with ethyl acetate and the combined organic layers
were washed with brine, dried over magnesium sulfate, filtered; concentrated and the
residue purified via chromatography on silica gel (5% 2M NH
3 in methanol/ 95% dichloromethane) to yield yellow oil, compound
171 (102 mg, 89.0% yield);
1H-NNM (DMSO-
d6) δ 7.73 (d, 1H, J= 3.4), 7.60 (d, 1H, J = 5.1), 7.45 (d, 1H, J = 8.2), 7.22 (d, 1H,
J = 3.0), 7.13-7.06 (m, 1H), 6.91 (s, 1H), 6.58 (d, 1H, J = 8.2), 6.39-6.28 (bar,
2 x m, 3H), 4.10 (t, 2H, J = 6.9), 2.16 (t, 2H, J = 7.0), 2.05 (s, 6H), 1.73 (quintet,
2H, J =7.5), 1.37 (quintet, 2H, J = 7.5); MS (ESI+): 341 (M+1, 100%).
Example 48. Preparation of N-[1-(3-Morpholin-4-yl-propyl)-1H-indol-6-yl]-thiophene-3-carboxamidine
dihydrochloride (173)
[0366]
[0367] 1-(3-Morpholin-4-yl-propyl)-6-nitro-1H-indole (149): Please see Example 40 for experimental details.
[0368] Di hydrochloride salt of N-[1-(3-Morpholin-4-yl-propyl)-1H-indol-6-yl]-thiophene-3-carboxamidine
(173): A solution of compound
149 (0.25 g, 0.864 mmol) in dry ethanol (5 mL) was treated with Pd-C (0.025 g), purged
with hydrogen gas and stirred for overnight (15 h) under hydrogen atm. (balloon pressure).
The reaction mixture was filtered through celite bed and washed with dry ethanol (2
× 20 mL). The combined ethanol layer was treated with thiophene-3-carboximidothioic
acid benzyl ester hydrobromide (0.54 g, 1.728 mmol) and the resulting mixture was
stirred for over night (16 h) at room temperature. The solvent was evaporated and
product was precipitated with ether (100 mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 30 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
172 as a free base. Foam,
1H-NMR (DMSO-
d6) δ 1.83-1.92 (m, 2H), 2.19 (t, 2H,
J= 6.9 Hz), 2.30 (brs, 4H), 3.56 (t, 4H,
J = 4.5 Hz), 4.13 (t, 2H,
J = 6.9 Hz), 6.05 (brs, 2H), 6.34 (d, 1H,
J = 3.0 Hz), 6.57 (d, 1H,
J = 8.4 Hz), 6.93 (brs, 1H), 7.20 (d, 1H,
J = 3.3 Hz), 7.44 (d, 1H,
J = 8.4 Hz), 7.54 (dd, 1H,
J = 2.7, 4.8 Hz), 7.63 (d, 1H,
J = 5.4 Hz), 8.12 (dd, 1H,
J = 1.2,3.0 Hz); ESI-MS (m/z, %): 369 (M
+, 100). A solution of above free base in methanol (5 mL) was treated with 1 M HCl
in ether (2.6 mL, 2.592 mmol) and stirred for 30 min. at room temperature. The solvent
was evaporated and crude was recrystallized from ethanol/ether to obtain compound
172 (0.287 g, 75%) as a solid. mp 105-108 °C.
Example 49. Preparation of_ N-[1-(3-morpholin-4-yl-propyl)-1H-indol-6-yl]-furan-2-carbozamidine
dihydrochloride (175)
[0369]
[0370] 1-(3-Morpholin-4-yl-propyl)-6-nitro-1H-indole (149): Please see Example 40 for experimental details.
[0371] Di hydrochloride salt of N-[1-(3-morpholin-4-yl-propyl)-1H-indol-6-yl]-furan-2-carboxamidine
(175): A solution of compound
149 (0.25 g, 0.864 mmol) in dry ethanol (5 mL) was treated with Pd-C (0.025 g), purged
with hydrogen gas and stirred for overnight (15 h) under hydrogen atm. (balloon pressure).
The reaction mixture was filtered through celite bed and washed with dry ethanol (2
× 20 mL). The combined ethanol layer was treated with benzyl furan-2-carbimidothioate
hydrobromide (0.51 g, 1.728 mmol) and the resulting mixture was stirred for over night
(16 h) at room temperature. The solvent was evaporated and product was precipitated
with ether (100 mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 30 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
174 as a free base. Foam;
1H-NMR (DMSO-
d6) δ 1.83-1.92 (m, 2H), 2.19 (t, 2H,
J= 6.9 Hz), 2.30 (brs, 4H), 3.56 (t, 4H,
J= 4.2 Hz), 4.13 (t, 2H,
J = 6.9 Hz), 6.00-6.20 (m, 2H), 6.33 (d, 1H,
J= 3.0 Hz), 6.55-6.62 (m, 2H), 6.98 (brs, 1H), 7.09 (d, 1H,
J= 3.3 Hz), 7.20 (d, 1H,
J= 3.0 Hz), 7.43 (d, 1H,
J= 8.1 Hz), 7.78 (brs, 1H); ESI-MS (m/z, %): 353 (M
+, 100). A solution of above free base in methanol (5 mL) was treated with 1 N HCl
in ether (2.6 mL, 2.592 mmol) and stirred for 30 min. at room temperature. The solvent
was evaporated and crude was recrystallized from ethanol/ether to obtain compound
175 (0.262 g, 71%) as a solid. mp 87-90 °C.
Example 50. Preparation of N-[1-(3-morpholin-4-yl-propyl)-1H-indol-6-yl]-furan-3-carboxamidine
dihydrochloride (177)
[0372]
[0373] 1-(3-Morpholin-4-yl-propyl)-6-nitro-1H-indole (149): Please see Example 40 for experimental details.
[0374] Di hydrochloride salt of N-[1-(3-morpholin-4-yl-propy)-1H-indol-6-yl]-furan-3-carboxamidine
(177): A solution of compound
149 (0.25 g, 0.864 mmol) in dry ethanol (5 mL) was treated with Pd-C (0.025 g), purged
with hydrogen gas and stirred for overnight (15 h) under hydrogen atm. (balloon pressure).
The reaction mixture was filtered through celite bed and washed with dry ethanol (2
× 20 mL). The combined ethanol layer was treated with benzyl furan-3-carbimidothioate
hydrobromide (0.51 g, 1.728 mmol) and the resulting mixture was stirred for over night
(16 h) at room temperature. The solvent was evaporated and product was precipitated
with ether (100 mL). The solid was dissolved into sat. NaHCO
3 sol.: CH
2Cl
2 (50 mL, 1:1). The org. layer was separated and aqueous layer was extracted with CH
2Cl
2 (2 × 30 mL). The combined CH
2Cl
2 layer was washed with brine (20 mL) and dried (Na
2SO
4). The solvent was evaporated and crude was purified by column chromatography (2M
NH
3 in methanol: CH
2Cl
2, 5:95) to obtain compound
176 as a free base. Foam;
1H-NMR (DMSO-
d6) δ 1.85-1.91 (m, 2H), 2.19 (t, 2H,
J= 6.6 Hz), 2.30 (brs, 4H), 3.56 (t, 4H,
J= 4.2 Hz), 4.13 (t, 2H,
J = 6.3 Hz), 6.00-6.07 (m, 2H), 6.34 (d, 1H,
J= 3.0 Hz), 6.56 (d, 1H,
J= 7.8 Hz), 6.90-6.92 (m, 2H), 7.20 (d, 1H,
J= 3.0 Hz), 7.43 (d, 1H,
J= 8.4 Hz), 7.70 (brs, 1H), 8.22 (brs, 1H); ESI-MS (m/z, %): 353 (M
+, 100). A solution of above free base in methanol (5 mL) was treated with 1 N HCl
in ether (2.6 mL, 2.592 mmol) and stirred for 30 min. at room temperature. The solvent
was evaporated and crude was recrystallized from ethanol/ether to obtain compound
177 (0.286 g, 78%) as a solid. mp 95-98 °C.
Example 51. Preparation of N-(3-(3-morpholinopropyl)-1H-indol-5-yl)thiophene-2-carboximidamide
hydrochloride (181):
[0375]
Preparation of 3-(5-bromo-1H-indol-3-yl)-N-morpholinepropanamide (178):
[0376] To an argon purged vial fitted with a magnetic stirbar was charged 5-bromo-indol-3-propionic
acid (
52) (542 mg, 2.02 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride
(426 g, 2.22 mmol) and 1-hydroxybenzotriazole (273 mg, 2.02 mmol). Anhydrous DMF (5
mL) was added, followed by morpholine (0.18 mL, 2.06 mmol) and triethylamine (0.65
mL, 4.66 mmol). The reaction was stirred for 21.5 hours at room temperature. The reaction
was diluted with ice-cold water (10 mL) and ethyl acetate (10 mL). The reaction was
transferred to a separatory funnel and the product was extracted into the organic
layer. The aqueous phase was extracted twice more with ethyl acetate (2x10 mL). The
combined organics were washed with brine (10 mL), dried over magnesium sulfate, filtered
and concentrated to afford a brown oil. Further drying under high vacuum afforded
a pale orange solid, compound
178. Yield: 541 mg orange solid (79.4%)
1H NMR (DMSO) δ 11.00 (br s, NH), 7.68-7.67 (d, 1H, J = 1.5), 7.31-7.28 (d, 1H, J =
8.4 Hz), 7.72-7.14 (td, 2H,
J= 1.8, 8.4 Hz), 2.93-2.81 (m, 8 H), 2.64 - 2.59 (t, J = 7.5 Hz, 2H).
Preparation of 4-(3-(5-bromo-1H-indol-3-yl)propyl)morpholine (179):
[0377] To an argon purged vial fitted with a magnetic stirbar containing compound
178(518 mg, 1.54 mmol) was added lithium aluminum hydride (146 mg, 3.84 mmol) followed
by anhydrous tetrahydrofuran (15 mL). The vial was placed in a metal heating block
and heated to reflux. After stirring at reflux for 21 hours, the reaction was cooled
to room temperature. The cooled reaction was quenched with water (0.15 mL), 3N sodium
hydroxide (0.25 mL), and water (0.45 mL) sequentially. The reaction was filtered through
celite to remove the white solid and the pale yellow filtrate concentrated to afford
a pale yellow oil. Drying under high vacuum afforded a pale yellow solid, compound
179. Yield: 407 mg of pale yellow solid (82%)
1H NMR (CDCl
3) δ 7.99 (s, 1H), 7.75 (s, 1H), 7.28 - 7.20 (m, 1H), 6.99 (s, 1H), 3.76 - 3.73 (t,
J = 4.5 Hz, 4H), 2.77 - 2.72 (t, J = 7.5 Hz, 2H), 2.46 - 2.39 (m, 6H), 1.94 -1.91
(m, 2H).
Preparation of 3-(3-morpholinopropyl)-1H-indol-5-amine (180):
[0378] To an argon purged vial fitted with a magnetic stirbar was charged a solution of
compound
179 (407 mg, 1.26 mmol) in anhydrous THF (8 mL). The orange solution was treated with
solid Pd
2(dba)
3 (58 mg, 0.063 mmol) which resulted in a dark red reaction mixture. Tri-t-butyl phosphine
solution (10%, 0.37 mL, 0.13 mmol) was added and the reaction was stirred at room
temperature for 5 minutes. A 1M solution of lithium bis(trimethylsily)amide in THF
(3.78 mL, 3.78 mmol) was added, and the yellow-brown solution placed in a metal heating
block and heated to reflux. The reaction was stirred at this temperature for 16 hours.
TLC (10% 2M ammonia in methanol, 90% dichloromethane) revealed all starting material
had reacted. The reaction was cooled to room temperature and quenched with 1M aqueous
hydrogen chloride (15 mL). The acidic reaction was extracted with ethyl acetate (3
x 10 mL). The aqueous phase was basified with 3N sodium hydroxide (8 mL) and partitioned
into ethyl acetate (3 x 10 mL). The organics were washed with brine, dried over magnesium
sulfate, and treated with charcoal. Filtration through celite, concentration and further
drying under high vacuum afforded a dark yellow oil. Purification of the product was
performed using silica gel column chromatography (5-10% 2M ammonia in methanol, 95-90%
dichloromethane) Yield: 102 mg of brown oil, compound
180 (31.2%).
1HNMR (CDCl3) δ 7.72 (br s, NH), 7.17-7.14 (d, 1H, J = 8.4 Hz), 6.92-6.89 (dd, 2H,
J = 2.1, 4.5 Hz), 6.67 - 6.64 (dd, J = 2.1, 8.4 Hz, 1H), 3.77 - 3.74 (t, J = 4.5 Hz,
4H), 2.74-2.69 (t, J = 7.5, 2H), 2.49 - 2.43 (m, 6H), 1.97 -1.89 (m, 2H).
[0379] Preparation of N-(3-(3-morpholinopropyl)-1H-indol-5-yl)thiophene-2-carboximidamide
hydrochloride (181) : To an argon purged vial fitted with a magnetic stirbar was charged a solution of
180 (28 mg, 0.108 mmol) in absolute ethanol (3 mL). Methyl thiophene-2-carbimidothioate
hydroiodide (62 mg, 0.217 mmol) was added as a yellow solid in one portion. The reaction
was stirred at room temperature for 17 hours. The reaction was complete by TLC (10%
2M ammonia in methanol, 90% dichloromethane). The reaction was diluted with ether
(15 mL) and the solid which precipitated was collected by vacuum filtration. The precipitate
was washed with ether (10 mL). The product was collected by washing the filter with
methanol (10 mL) and collecting the filtrate. The filtrate was returned to the reaction
vial and DOWEX-66 (3 g) was added. The reaction was stirred for 2 hours. The reaction
was filtered and the filtrate concentrated to afford a brown solid. The solid was
taken up in dichloromethane (10 mL) and partitioned with saturated sodium bicarbonate
(2 mL). The organic phase was treated with brine, dried over magnesium sulfate and
filtered. The filtrate was treated with 1M hydrogen chloride in ether (3 mL). After
stirring for 1 hours the reaction was concentrated on the rotary evaporator. The resulting
yellow solid was dried further on the high vacuum line. Yield: 45 mg of yellow solid,
compound
181 (96%).
1H NMR (DMSO) δ 10.91 (br s, 1H), 7.96 (s, 2H), 7.42 - 7.39 (d, J = 8.4 Hz, 2H), 7.36
(s, 1H), 7.29 - 7.25 (t, J = 4.5 Hz, 1H), 7.24 (s, 1H), 6.92 - 6.89 (d, J = 8.7 Hz,
1H), 3.58 (s, 4H), 2.72 - 2.67 (t, J = 7.5 Hz, 2H), 2.38 (m, 6H), 1.83-1.78 (m, 2H).
MS (ESI+): 369 (MH+, 100%).
NOS In Vitro Inhibition Assays
[0380] The compounds of formula I of the present invention have been found to exhibit selective
inhibition of the neuronal isoform of NOS (nNOS). Compounds may be examined for their
efficacy in preferentially inhibiting nNOS over iNOS and/or eNOS by a person skilled
in the art, for example, by using the methods described in Examples 11 a and 11b,
herein below.
Example 52a: nNOS (rat), eNOS (bovine) and iNOS (murine) Enzyme Assay
[0381] The NOS isoforms used in this example were recombinant enzymes expressed in
E. coli. Rat nNOS was expressed and purified as described previously (
Roman et al., Proc. Natl. Acad Sci. USA 92:8428-8432, 1995). The bovine eNOS isoform was isolated as reported (
Martasek et al., Biochem. Biophys. Res. Commun. 219:259-365, 1996) and murine macrophage iNOS was expressed and isolated according to the procedure
of
Hevel et al. (J. Biol. Chem. 266:22789-22791, 1991). IC
50 values and percent inhibition of NOS by the compounds of the invention were determined
under initial velocity measurement conditions with the hemoglobin capture assay as
previously described (
Hevel and Marletta, Methods Enzymol. 133:250-258, 1994). In this assay, nitric oxide reacts with oxyhemoglobin to yield methemoglobin, which
was detected at 401 nm (e = 19,700 M
-1cm
-1) on a Perkin-Elmer Lamda 10 UV/vis spectrophotometer. The assays were performed using
varying test compound concentrations. Assay mixtures for nNOS or eNOS contained 10
mM L-arginine, 1.6 mM CaCl
2, 11.6 mg/mL calmodulin, 100 mM NADPH, 6.5 mM BH
4 and 3 mM oxyhemoglobin in 100 mM Hepes (pH 7.5). Assay mixtures for iNOS contained
10 mM of L-arginine, 100 mM NADPH, 6.5 mM BH
4 and 3 mM oxyhemoglobin in 100 mM Hepes (pH 7.5). All assays were conducted in a final
volume of 600 µL and were initiated with enzyme. Results for exemplary compounds of
the invention are shown in Table 2a. These results indicate the selectivity of the
compounds of the invention for nNOS inhibition.
TABLE 2a. Selective inhibition of NOS by compounds of the Invention
Compound |
Rat nNOS (µM) |
Murine iNOS (µM) |
Bovine eNOS (µM) |
4 |
29.6 |
46.9 |
164 |
5 |
57.6 |
- |
643 |
9 |
9.4 |
|
29.2 |
12 |
8.8 |
109 |
211 |
15 |
2.3 |
56 |
51.1 |
18 |
3.3 |
43.5 |
248 |
24 |
3.7 |
213.3 |
103 |
27 |
14.6 |
159.2 |
>300 |
32 |
4.1 |
67.2 |
6.2 |
Example 52b: nNOS (human), eNOS (human) and iNOS (human) Enzyme Assay
[0382] Recombinant human inducible NOS (iNOS), human endothelial constitutive NOS (eNOS)
or human neuronal constitutive NOS (nNOS) were produced in Baculovirus-infected Sf9
cells (ALEXIS). In a radiometric method, NO synthase activity was determined by measuring
the conversion of [
3H]L-arginine to [
3H]L-citrulline. To measure iNOS, 10 µL of enzyme was added to 100 µL of 100 mM HEPES,
pH=7,4, containing 1mM CaCl
2, 1 mM EDTA, 1 mM dithiothreitol, 1 µM FMN, 1 µM FAD, 10 µM tetrahydrobiopterin, 120
µM NADPH, and 100 nM CaM. To measure eNOS or nNOS, 10 µL of enzyme was added to 100
µL of 40 mM HEPES, pH = 7.4, containing 2.4 mM CaCl
2, 1mM MgCl
2, 1mg/mL BSA, 1mM EDTA, 1 mM dithiothreitol, 1µM FMN, 1µM FAD, 10 µM tetrahydrobiopterin,
1mM NADPH, and 1.2 µM CaM.
[0383] To measure enzyme inhibition, a 15 µL solution of a test substance was added to the
enzyme assay solution, followed by a pre-incubation time of 15 min at RT. The reaction
was initiated by addition of 20 µL L-arginine containing 0.25 µCi of [
3H] arginine/mL and 24 µM L-arginine. The total volume of the reaction mixture was
150 µL in every well. The reactions were carried out at 37°C for 45 min. The reaction
was stopped by adding 20 µL of ice-cold buffer containing 100 mM HEPES, 3 mM EGTA,
3 mM EDTA, pH = 5.5. [
3H]L-citrulline was separated by DOWEX (ion-exchange resin DOWEX 50 W X 8-400, SIGMA)
and the DOWEX was removed by spinning at 12,000 g for 10 min in the centrifuge. An
70 µL aliquot of the supernatant was added to 100 µL of scintillation fluid and the
samples were counted in a liquid scintillation counter (1450 Microbeta Jet, Wallac).
Specific NOS activity was reported as the difference between the activity recovered
from the test solution and that observed in a control sample containing 240 mM of
the inhibitor L-NMMA. All assays were performed at least in duplicate. Standard deviations
were 10% or less. Results for exemplary compounds of the invention are shown in Table
2b. These results again show the selectivity of the compounds of the invention for
nNOS inhibition.
TABLE 2b. Selective inhibition of human NOS by compounds of the Invention
Compound |
Human nNOS (µM) |
Human iNOS (µM) |
Human eNOS (µM) |
12 |
1.2 |
60 |
15 |
18 |
2.6 |
12 |
26 |
27 |
12 |
320 |
>100 |
32(+) |
0.32 |
72.8 |
16 |
32(-) |
0.2 |
72.6 |
24 |
37 |
0.49 |
21 |
3.8 |
Neuroprotection Studies
[0384] The neurotoxic effects of glutamate through the activation of NMDA receptors and
Ca
2+ influx contribute to neuronal degeneration in several neurological diseases (
Choi, J. Neurobiol. 23:1261, 1992;
Dingledine et al., Trends Pharmacol. Sci. 11:334-338, 1990;
Meldrum and Garthwaite, Trends Pharmacol. Sci. 11:379-387, 1990). Thus, compounds that prevent cell death associated with activation of NMDA receptors,
either directly via NMDA antagonism (Example 12-15), or indirectly through blocking
NMDA mediated NO synthesis, are candidate neuroprotective agents for the treatment
of neurodegenerative diseases.
Example 53: Neuroprotection of Rat Cortical Cells Against NMDA Challenge
[0385] According to a previously reported procedure (
Tremblay et al., J Neurosci. 20(19):7183-92, 2000), test compounds were added for a 60-minute pre-incubation period to rat cortical
neuronal cultures, which were then exposed for 30 minutes to 25 µM NMDA in buffer.
After 24 hrs cultures were treated with propidium iodide and the % cell death determined
and compared to control cells. As shown in Figure 1, compounds
9, 12, and
18 protected neuronal cells from death upon NMDA challenge, indicating their efficacy
as neuroprotective agents.
Example 54: Neuroprotection of Rat Hippocampal Slices after Oxygen-Glucose Deprivation
(OGD)
[0386] Given that during stroke, ischemia, and trauma, the brain is deprived of oxygen and
nutrients, OGD represents a more "physiological" insult to cortical cultures and thus
is a relevant model of neuroprotection. Neuronal cultures were exposed to 90 minutes
of hypoxia in glucose-free buffer with or without compound
9, 12, or
18. A 60-minute pre-incubation period with compound
12 was used in those cultures treated with this compound. After 24 hours, propidium
iodide was used to determine cell death. As shown in Figure 2, a concentration of
25 µM of compound
12 protected neurons against the 90-minute OGD insult, indicating its efficacy as a
neuroprotective agent
Example 55: Effects on NMDA induced Ca2+Influx by Compound 12
[0387] To measure intracellular [Ca
2+]
i concentrations in neuronal cultures, cells were loaded with the fluorescent Ca
2+-sensitive dye Fluo-4FF. Flourescence was read on a plate reader before and after
a 15 minute application of NMDA (25 µM). NMDA induces a rapid transient elevation
of [C
2+]
i. As shown in Figure 3, compound
12 caused a dose-dependent (10-50 µM) inhibition of NMDA-induced Ca2
+ influx, indicating its efficacy as an NMDA antagonist and as a neuroprotective agent.
Example 56: Effects on NMDA-Induced Whole-Cell Currents in Rat Cortical Neurons by
Compound 12
[0388] Effects of compound
12 on NMDA-induced currents in whole-cell rat cortical neurons was performed according
to literature procedures (
Mealing et. al. J Pharmacol Exp Ther. 2001 297(3), 906-14). As shown in Figure 4, compound
12 effectively blocked NMDA-induced currents in rat whole-cell cortical neurons in a
dose-dependent manner, demonstrating its efficacy as an NMDA antagonist and as a neuroprotective
agent.
Example 57: Effects of NOS Inhibitors on Formalin-Induced Paw Licking in Mice.
[0389] Formalin Induced Hyperalgesia and Inflammation: In an experimental model of sustained
inflammatory nociception associated with long term intracellular changes of nociceptive
processing at the level of the spinal cord, mice or rats are subjected to a subplantar
injection of formalin into a paw (
Chapman et al., Brain Res. 697:258-261, 1995;
Meller and Gebhart, Pain 52:127-136, 1993). Two distinct phases of spontaneous nociceptive behaviour exist: The first phase
(Phase I) last about 5 minutes, followed by a second phase (Phase II), lasting approximately
40 minutes characterized by persistent shaking or licking of the injected paw (
Fu et al., Neuroscience 101 (4):1127-1135, 2000). Longer periods after injection of formalin results in the development of allodynia
and hyperalgesia (1-4 weeks). It has been shown previously that 7-NI exhibits anti-nociceptive
activity in mice without increasing blood pressure (
Moore et al., Br. J. Pharmacol. 102:198-202, 1992). Thus, compounds possessing n-NOS inhibitory activity should be effective for the
treatment of inflammatory pain and neuropathic pain symptoms of allodynia and hyperalgesia
resulting from inflammation.
[0390] Test compounds, including compound
12 and 7-NI, were dissolved in 1% DMSO/2% Tween 80/0.9% NaCl. Male or female ICR-derived
mice weighing 23 ± 2 g were housed in A.PEC
® cages and maintained in a controlled temperature (22°C - 24°C) and humidity (60%-80%)
environment with 12 hr light-dark cycles for 1 week prior to use. Free access to standard
lab chow and tap water was granted. Test substances were administered intraperitoneally
to 6 groups of 5 ICR-derived mice, weighing 23 ± 2 g, 30 minutes before subplantar
injection of formalin (0.02 mL, 1%). The reduction of formalin-induced hind paw licking
time was recorded during the following 20 to 30 minute period (Phase II). As shown
in Figure 5, administration of both compound 12 and 7-NI resulted in a reduction in
the frequency of paw licking in the subject mice, indicating the efficacy of this
compound as a treatment for pain.
Example 58: Neuroprotective Effect in a Mouse Model of Traumatic Brain Injury (TBI)
by Compound of Formula 12
[0391] Traumatic Brain Injury Test: Male Swiss mice (Iffa Credo, France), weighing 21 to
24 g, were given water and food
ad libidum before the experiment. The traumatic brain injury (TBI) model used in the experiment
was the closed head injury model described by
Hall (J. Neurosurg. 62:882-887, 1985) and modified according to
Mésenge (J. Neurotrauma 13:209-214, 1996). Mice were held by the dorsal skin of the neck and the head was positioned under
the injury apparatus, with the chin resting firmly on the base of the apparatus. The
injury weight was then released, falling freely to hit a metal impounder resting on
the top of the head. A 50-g weight was dropped 24 cm resulting in a 1200g/cm impact
injury. Injury caused immediate unconsciousness, as judged by the loss of righting
reflex and the loss of any pain reflex. The loss of conciousness lasted 2-5 min. Of
the mice 20-30% died in the first post-traumatic seconds. There was no delayed mortality
or prostration in the surviving mice, with test animals taking water and food similarly
to control animals.
[0392] Neurological Deficit Evaluation: Neurological examinations were performed in a blinded
fashion 1h, 4h, and 24h after TBI on compound
12-treated uninjured mice and, control mice treated with vehicle alone, and compound
12-treated injured mice. Sensorimotor status was evaluated blindly by a grip test and
a string test, as described by
Hall (J. Neurosurg., 62:882-887, 1985). Each mouse was picked up by the tail and placed on a taut string 60 cm long suspended
between two upright bars 40 cm above a padded table. The grip score was measured as
the length of time (in seconds) during which the mouse remained on the string in some
manner, with a cut-off of 30 seconds. The string test, scoring from 0 (severely impaired)
to 5 (normal) evaluated the way mice could hang and move on the string, with the following
scoring criteria: 0 - mice fall during the 30-second period evaluation; 1 - mice hang
on the string during the 30-second period evaluation, using only one paw; 2 - mice
hang on the string using the four paws, at least 5 seconds; 3 - mice hang on the string
using four paws and the tail, at least 5 seconds; 4 - mice hang on the string using
the four paws and the tail and move, at least 5 seconds; and 5 - mice reach one of
the upright bars during the 30 - second period evaluation.
[0393] One hour after TBI, no significant improvement in the string score (Figure 6, Table
3) or in the Hall scores (Figure 7, Table 4) was observed in the control mice or in
the treated mice. However, 4 hours following TBI, a significant improvement in the
string scores (Figure 8, Table 5) for the 3 and 6 mg/kg treatment group and in grip
score for the 3 mg/kg treatment group with a trend towards improvement in the 6 mg/kg
group (Figure 9, Table 6). A significant improvement in the Hall score was observed
for the 6 mg/kg treatment group 4 hours after TBI (Figure 10, Table 7). A non-significant
trend towards improvement was observed after 24 hours in the string, grip and Hall
scores for treated groups relative to control was observed after a single s.c. dose
of compound
12. These results indicate a neuroprotective effect of compound
12 following traumatic brain injury.
[0394] Body Temperature and Weight Loss: Body temperature and weight loss were recorded
for uninjured mice, and for injured treated and control mice mice at 1, 4, and 24
hours after injury. One hour post TBI, a significant drop in body temperature was
noted in injured mice, with no difference between treated and control mice (Figure
11, Table 8). At 4 hours post TBI, untreated animals had a significant elevated body
of 37.1 while the average body temperature of the treated mice was similar to uninjured
mice (Figure 12, Table 9). At 24 hours injured control mice and low-dose treated mice
(1 mg/kg) had a lower body temperature than uninjured or injured mice treated with
3 or 6 mg/kg.
[0395] Injured mice had a significant loss of body weight 24 hours after TBI relative to
uninjured mice (Figure 13, Table 10). However, a significant improvement in body weight
was observed for mice in the 3 mg/kg treatment group. A reduction of body mass and
growth rate is a characteristic secondary phenomenon associated with acute brain trauma
partly due to hypercatabolism of the damaged brain tissue (
J.L. Pepe and C.A. Barba, J. Head Trauma Rehabil. 14: 462-474, 1999;
Y.P. Tang et al. J. Neurotrauma 14: 851-862, 1997). Therefore, a reduction in the loss of body weight is further indication of the
neuroprotective effect of compound
12 following traumatic brain injury.
Example 59: Neuroprotection in CA1 Hippocampal Slices after OGD
[0396] Brain slice preparations are a valuable tool to study mechanisms underlying neurotoxicity
and to assess the protective potential of new neuroprotective therapeutic agents.
For example, nitric oxide inhibitors have been shown to attenuate OGD-induced damage
(
Izumi et al., Neuroscience Letters 210:157-160, 1996) and to block anoxic preconditioning (
Centeno et al., Brain Research 836:62-69, 1999) in acute rat hippocampal slices. Slice preparations allow precise control of the
neuronal environment, thus allowing both ionic and pharmacological manipulations not
possible
in vivo. The hippocampal slice model is especially useful for studying ischemia-induced neurotoxicity,
since its CA1 neurons are among the most sensitive to neuronal injury. Furthermore,
the hippocampal slice preserves physiological neuronal-glial cell interactions and
synaptic circuitry, and retains its functional viability well beyond 6 h. Orthodromic
stimulation of the Schaffer collateral input to neurons in the CA1 and subsequent
measurement of field potentials near the pyramidal cell bodies of the CA1 neurons
has been a method of choice for assessing viability in this model (see Figure 14).
[0397] Brain injury can be measured in brain sections by incubating sections of fresh brain
in 2,3,5-triphenyltetrazolium chloride (TTC). TTC, which is colorless, is reduced
by mitochondrial succinate dehydrogenase in living tissue to a red formazan product.
Combinations of photography or scanning and image analysis are then used to measure
the area of normal (red) and damaged (uncolored) tissue at the surface of each section
face and estimate the extent of damage. The TTC staining technique has been further
refined by members of the Experimental Stroke Group at IBS (Study Host: University
of Ottawa, Canada) using a solvent to extract the colored formazan product from tissue
sections and measured it spectrophotometrically, thus obtaining a simple, objective
measure of damage (
Preston and Webster, J. Neurosci. Meth. 94(2):187-92, 1999).
Watson et al. (J. Neurosci. Meth. 53:203-208, 1994) have demonstrated a correlation between TTC reaction product and population spike
amplitude. A modified version of the technique of Preston and Webster was applied
to hippocampal slices in combination with field potential measurements of population
spike amplitude to screen for neuroprotective effects of compounds of the invention,
such as, for example, compound
12.
[0398] Slice Preparation: Male Wistar rats, 180-200 gm, were anesthetized with halothane
and decapitated. Their brains were removed and placed in artificial cerebral spinal
fluid (ACSF) at 0.5°C within 60 s of decapitation. Composition of the ACSF was (in
mM): 127 NaCl, 2 KCl, 1.2 KH
2PO
4, 26 NaHCO
3, 2 MgSO
4, 2 CaCl
2, 10 glucose, equilibrated with 95% O
2/5% CO
2, pH 7.4. Brains were hemisected and hippocampi were dissected out and sectioned into
400 µM thick slices using a McIlwain Tissue chopper (Mickle Laboratory Engineering
Co. Gomshall, GB). Sectioning was initiated approximately 1 mm from the rostral end
of the hippocampus and approximately 12 slices were harvested from each hippocampus.
Slices were distributed into groups in a rotational manner so that each group contained
slices from all sectioned regions of the hippocampus. The hippocampal slices were
placed on nylon mesh platforms in interface-type incubation chambers (6-8 slices per
platform; 1 platform per chamber) for 90 min at 35 °C. The ACSF in these chambers,
and the atmosphere above it, was continuously gassed with 95% O
2/5% CO
2. In some instances, after an initial 60 min stabilization period, slices received
a pre-insult treatment by transferring the slices on their nylon mesh platform to
another chamber for a 30 main incubation in the appropriate ACSF. The slices that
were subjected to a 10 min oxygen-glucose deprivation (OGD) were transferred on their
nylon mesh platforms to incubation chambers that contained anoxic, low glucose (4
mM) ACSF. The ACSF in these chambers and the atmosphere above it was continuously
gassed with 95% N
2/5% CO
2. Following this 10 min insult the platforms supporting the slices were returned to
their original incubation chambers and maintained for a period of 4 h.
[0399] Treatment Groups: For every experiment, three control groups were run:
control live (4 h after sham insult),
control dead (4 h after 10 min OGD insult), and
control protection (4 h post 10 min OGD insult in 0.3 mM Ca, with 30 min preincubation). In experiments
where
control live slices didn't survive,
control dead slices didn't die, or
control protection slices were not significantly better than those in the
control dead group, the entire experiment was rejected.
- (a) Preservation of Evoked Field Potentials: The efficacy of synaptic transmission
in these slices was evaluated using electrophysiological techniques. Slices were transferred
to an interface recording chamber (Haas et al., J. Neurosci. Meth. 1:323-325, 1979) and perfused at a rate of 1 mL/min at 35.0 ± 0.5 °C. Orthodromic field potentials
were evoked by stimulating the Schaffer collaterals with a concentric bipolar tungsten
electrode. Stimulation consisted of 2 ms duration constant-current pulses separated
by 30 s intervals. Evoked potentials (EP) were recorded in the CA1 from the stratum
pyrimidale using glass micropipettes (2-5 megohms) filled with 150 mM NaCl. Population
spike (PS) amplitude was measured from the peak downward deflection to the midway
point between the 2 positive peaks. PS amplitude was optimized by adjusting the recording
electrode within the slice, usually to a depth of about 50 µM. In slices whose PS
was less than 3 mV in amplitude, a 2nd and, if necessary, a 3rd attempt was made to obtain a more robust PS, by relocating the recording electrode
within the CA1. The largest amplitude PS from these multiple recording attempts was
tabulated.
In control slices, PS amplitude was not affected by 50 µM compound 12 (Figure 14; control left, compound 12 right). In Figure 15, traces show PS's recorded from control slices (left), slices
subjected to OGD (middle) and slices subjected OGD in 0.3 mM Ca2+. Each trace is the average of 10 consecutively recorded field potentials; 0.03 Hz
stimulation. Hippocampal slices not subjected to an OGD insult (control live) had a PS amplitude of 3.5 ± 0.5 mV (n = 12). Slices exposed to 10 min OGD (control dead) showed fiber volleys, but no PSs (n = 5), whereas slices exposed to the same insult,
but incubated in 0.3 mM Ca2+30 min prior to and during the insult (control protection) had a PS amplitude of 1.4 ± 0.3 mV (n = 3) (Figure 16).
Slices incubated in 0.05% DMSO alone (the maximum concentration of vehicle used for
7-NI) and exposed to OGD, as per the treatment groups, had PS amplitudes not significantly
different from the control dead group. Slices incubated with 100 µM 7-NI showed fiber volleys, but no PSs (n = 3).
Slices treated with 50 µM compound 12 had PS amplitudes of 2.1 ±1.5 mV (n = 3). All of these results indicate a neuroprotective
effect of compound 12.
- (b) Preservation of Mitochondrial Metabolic Activity by compound 12 using TTC staining: Hippocampal slices exposed to 10 min OGD (control dead) retained 25 ± 5 % (n = 5 groups of 4-5 slices) of the absorbance of slices not subjected
to an insult (control live - normalized to 100%), whereas slices preincubated in 0.3 mM calcium 30 min prior to
and during OGD retained 107 ±27% (n = 5) of their absorbance (control protection). Slices incubated in 0.05% DMSO alone (the maximum concentration of vehicle used for
7-NI) and exposed to OGD, as per the compound treatment groups, had absorbances not
significantly different from the control dead group (data not shown). Slices treated with 100 µM 7-NI retained 81 ±18% (n = 5)
of their absorbance, while slices treated with 50 µM compound 12 retained 92 ±18% (n = 8) of their absorbance (see Figure 17). These results again
indicate a neuroprotective effect for compound 12.
Example 60: Efficacy in Models Predictive of Neuropathic-like Pain States
[0400] The efficacy of the compounds of the invention for the treatment of neuropathic pain
was assessed using standard animal models predictive of antihyperalgesic and anti-allodynic
activity induced by a variety of methods, each described in more detail below.
- (a) Chung Model of Injury-induced Neuropathic-like Pain: The experimental designs
for the Chung Spinal Nerve Ligation SNL Model assay for neuropathic pain are depicted
in Figure 18. Nerve ligation injury was performed according to the method described
by Kim and Chung (Kim and Chung, Pain 50:355-363,1992). This technique produces signs of neuropathic dysesthesias, including
tactile allodynia, thermal hyperalgesia, and guarding of the affected paw. Rats were
anesthetized with halothane and the vertebrae over the L4 to S2 region were exposed.
The L5 and L6 spinal nerves were exposed, carefully isolated, and tightly ligated
with 4-0 silk suture distal to the DRG. After ensuring homeostatic stability, the
wounds were sutured, and the animals allowed to recover in individual cages. Sham-operated
rats were prepared in an identical fashion except that the L5/L6 spinal nerves were
not ligated. Any rats exhibiting signs of motor deficiency were euthanized. After
a period of recovery following the surgical intervention, rats show enhanced sensitivity
to painful and normally non-painful stimuli.
[0401] After one standard dose (10 mg/kg) injected IP according to the published procedure,
there is a clear antihyperalgesic effect of nNOS selective compounds
32(-), 32(+) (see Figure 19), and
12 (see Figure 21). Administration of compounds
32(-),
32(+), and
12 to test animals also resulted in a reversal of tactile hyperthesia (see Figures 20
and 22, respectively). A clear difference between the two enantiomers of compound
32 was observed in this model of neuropathic pain.
Example 61: Experimental migraine model
[0402] Animals. Male, Sprague Dawley rats (275-300g) were purchased from Harlan Sprague Dawley (Indianapolis,
IN). Animals were given free access to food and water. Animals were maintained on
a 12 hour light (7am to 7pm) and 12 hour dark cycle (7pm to 7am). All procedures were
in accordance with the policies and recommendations of the International Association
for the Study of Pain and the National Institutes of Health guidelines and use of
laboratory animals as well as approved by the Animal Care and Use Committee of the
University of Arizona.
Surgical Preparation.
[0403] Migraine cannulation: Male Sprague Dawley rats were anesthetized using ketamine/xylazine (80mg/kg, i.p.),
the top of the head was shaved using a rodent clipper (Oster Golden A5 w/size 50 blade),
and the shaved area was cleaned with betadine and 70% ethanol. Animals were placed
into a stereotaxic apparatus (Stoelting model 51600) and the body core temperatures
of 37°C were maintained using a heating pad placed below the animals. Within the shaved
and cleaned area on the head, a 2 cm incision was made using a scalpel with a #10
blade and any bleeding was cleaned using sterile cotton swabs. Location of bregma
and midline bone sutures were identified as references and a small hole 1 mm in diameter
was made using a hand drill without breaking the dura but deep enough to expose the
dura. Two additional holes (1 mm in diameter) 4 to 5 mm from the previous site were
made in order to mount stainless steel screws (Small Parts #A-MPX-080-3F) securing
the cannula through which an inflammatory soup could be delivered to induce experimental
migraine. A modified intracerebroventricular (ICV) cannula (Plastics One #C313G) was
placed into the hole without penetrating into or through the dura. The ICV cannula
was modified by cutting it to a length of 1 mm from the bottom of the plastic threads
using a Dremel mototool and a file to remove any steel burrs. Once the modified migraine
cannula was in place, dental acrylic was placed around the migraine cannula and stainless
steel screws in order to assure that the cannula was securely mounted. Once the dental
acrylic was dry (i.e., after 10-15 min) the cap of the cannula was secured on top
to avoid contaminants entering the cannula and the skin was sutured back using 3-0
silk suture. Animals were given an antibiotic injection (Amikacin C, 5 mg/kg, i.m.)
and removed from the stereotaxic frame and allowed to recover from anesthesia on a
heated pad. Animals were placed in a clean separate rat cage for a 5 day recovery
period.
Injections. Subcutaneous injections: Subcutaneous (s.c.) injections were performed by manually holding the animal and
inserting a 25 gauge disposable needle on a disposable 1 cc syringe into the abdominal
region of the animal assuring that the needle remained between the muscle and the
skin of the animal. Injections of compounds were performed over a 5 sec period and
were noted as positive by the development of an out-pocketing of the skin at the site
of injection. Oral delivery was accomplished by using an
18 gauge gavage needle attached to a 1 cc syringe.
Migraine cannula injections: An injection cannula (Plastics One, C313I cut to fit the modified ICV cannulas) connected
to a 25 µl Hamilton Syringe (1702SN) by tygon tubing (Cole-Palmer, 95601-14) was used
to inject 10 µl of the inflammatory mediators solution onto the dura.
Behavioral Testing. Naive animals prior to the day of migraine surgery are placed in suspended plexiglass
chambers (30cm L X 15cm W X 20cm H) with a wire mesh bottom (1cm
2) and acclimated to the testing chambers for 30 minutes.
Hindpaw sensory thresholds to non-noxious tactile stimuli in rats
[0404] The paw withdrawal thresholds to tactile stimuli were determined in response to probing
with calibrated von Frey filaments (Stoelting, 58011). The von Frey filaments were
applied perpendicularly to the plantar surface of the hind paw of the animal until
it buckles slightly, and is held for 3 to 6 sec. A positive response was indicated
by a sharp withdrawal of the paw. The 50% paw withdrawal threshold was determined
by the non-parametric method of Dixon (1980). An initial probe equivalent to 2.00
g was applied and if the response was negative the stimulus was increased one increment,
otherwise a positive response resulted in a decrease of one increment. The stimulus
was incrementally increased until a positive response was obtained, then decreased
until a negative result was observed. This "up-down" method was repeated until three
changes in behavior were determined. The pattern of positive and negative responses
was tabulated. The 50% paw withdrawal threshold is determined as (10
[Xf+kM])/10,000, where Xf = the value of the last von Frey filament employed, k = Dixon value
for the positive/negative pattern, and M = the mean (log) difference between stimuli.
Only naive animals with baselines of 11 to 15g were used in the experiment Fifteen
grams was used as the maximal cut-off. Five days post migraine surgery animals paw
withdrawal thresholds were re-tested using the same habituation and von Frey procedure
as stated above. Data were converted to % "antiallodynia" by the formula: % activity
= 100 x (post-migraine value - baseline value)/(15 g - baseline value). Only animals
that demonstrated no difference in their tactile hypersensitivity as compared to their
pre-migraine surgery values were used in all studies.
[0405] After establishing baseline paw withdrawal thresholds, individual animals were removed
from the testing chamber, the cap of the migraine cannula was removed and animals
received an injection of either a mixture of inflammatory mediators (1mM Histamine,
1mM 5-HT [Serotonin], 1mM Bradykinin, 1mM PGF
2) or vehicle at 10uL volume via the migraine cannula over a 5 to 10 second period.
The inflammatory mediator (IM) cocktail was made fresh on the day of each experiment.
The cap of the migraine cannula was replaced, individual animals were placed back
into their corresponding testing chamber and paw withdrawal thresholds were measured
at 1 hour intervals over a 6 hour time course. Data were converted to % "antiallodynia"
by the formula: % activity = 100 x (post-IM value - pre-IM baseline value)/(15 g -
pre-IM baseline value).
[0406] Data on selected compounds of the invention obtained using this model are shown in
Figure 23. Application of an inflammatory soup (IS) onto the dura results in a decrease
in the hindpaw withdrawal threshold upon stimulation with von Frey filaments. Administration
of Sumatriptan succinate (1 mg/kg s.c.) 5 minutes prior to the addition of the soup
results in the prevention of the development of hindpaw allodynia as measured two
hours after IS administration. Similarly the non-selective NOS inhibitor L-NMMA (10
mg/kg i.v) or
42 and
97 (6 mg/kg i.v.) 10 minutes prior to IS prevents the development of hindpaw allodynia.
Thus non selective NOS inhibitors such as L-NMMA, or more selective nNOS inhibitors
(e.g., compound
97) or mixed nNOS/5HT1D/1B compounds (e.g., compound
42) should be effective for the treatment of migraine.
Example 62: Serotonin 5HT1D/1B Binding Assays
[0407] 5-HT1D binding assays (agonist radioligand)were performed using bovine caudate membranes
according to the methods of
Heuring and Peroutka (J. Neurosci 1987, 7: 894-903). 5-HT1B (rat cerebral cortex) binding assays (agonist radioligand) were performed
according to the method of
Hoyer et. al. (Eur. J. Pharmacol.1995, 118: 1-12). For the purpose of result analysis, the specific ligand binding to the receptors
is defined as the difference between the total binding and the nonspecific binding
as determined in the presence of an excess of unlabelled ligand. The results are expressed
as a percent of control specific binding obtained in the presence of the test compounds.
IC
50 values (concentration causing a half-maximal inhibition of control specific binding)
and Hill coefficients (
nH) were determined by non-linear regression analysis of the competition curves using
Hill equation curve fitting and the inhibition constants (K
i) were calculated from the Cheng Prusoff equation (K
i = IC
50/(1+(L/K
D)), where L = concentration of radio ligand in the assay, and K
D = affinity of the radioligand for the receptor).
Other embodiments
[0408] While the present invention has been described with reference to what are presently
considered to be the preferred examples, it is to be understood that the invention
is not limited to the disclosed examples. To the contrary, the invention is intended
to cover various modifications and equivalent arrangements included within the scope
of the appended claims.
[0409] Other embodiments are in the claims.